A word on aquarium science
Fishkeeping is a subjective science. I say subjective, because
there are many ways to accomplish the same task. I say science, because there
are some hard and fast rules that must b e adhered to. That said, we hope to
give you information on one o the ways to maintain a successful aquarium. It's
not the only way. It may not even be the best way. But it a way that is proven
and works. We also hope to provide you with the science behind aquariums to
make educated decisions about your aquarium.
Types of Aquariums
An
aquarium is a container that houses aquatic life, whereas a terrarium is a
container that houses live plants and animals.
A
wide variety of commercially available aquariums are designed specifically for
marine organisms. The large number of
styles, shapes, and sizes will fit just about anyone’s tastes. Designs include freestanding rectangular
tanks, hexagon tanks, curved front tanks, and models that resemble a coffee
table. Many manufactures will build a
custom design upon request. Regardless of shape, there are two basic building
materials, Glass, and acrylic. There are advantages and disadvantages o each.
All Glass Aquariums
The
most common type of aquarium is an all glass tank. Capacity will vary from 2.5 gallons to
hundreds of gallons. All glass tanks are
constructed of plate glass, held in place by silicone gel. The thickness of the glass increases as the
size increases. The tank is then finished
with a molding to protect the sharp edges of the glass.
A
glass aquarium may be used for either saltwater or freshwater setups. Never use a metal frame aquarium for a marine
setup- as it will react with the salts in the water and become toxic. All glass aquariums are relatively cheap,
readily available, and long lasting.
Some of the disadvantages are the weight of the larger glass aquariums
and difficulty in moving them around.
When
you purchase an all glass tank- be sure to inspect it for cracks, and closely
inspect al the silicone seals for signs of poor workmanship. And irregular seal along an inside joint
could eventually lead to a leak.
Acrylic Aquariums
Acrylic
plastics are strong and can be molded into many shapes and contours. Any acrylic pieces are joined with special
acrylic cement. Most aquariums of this
variety feature curved fronts, curved corners, and colored backs. Many include built in filtration systems, as
well as other features.
Some
advantages of acrylic aquariums re the fact it's relatively lightweight. A 100-gallon acrylic tank weighs much less
than the glass counterpart. Modern
acrylics are very scratch resistant.
Although this is also a disadvantage.
Acrylic can be scratched by many cleaning devices and decorations. But many commercial cleansers are available
to prevent this. Another disadvantage
with acrylic tanks is the initial high cost of getting an acrylic tank.
SIZE
Determining
the proper size of the aquarium depends on the number and type of fish, the
available space and economic constraints.
To the new marine tank hobbyist, the largest tank one can afford is
best.
Marine
aquariums should be larger than their freshwater counterparts. Whereas a 10-gallon tank can be perfectly
suitable for freshwater tropical fish, the same size can be quite vexing to the
new saltwater hobbyist. Many species of
marine fish are very territorial and require large spaces to coexist
peacefully. Since an aquarium is an
enclosed body of water, this small volume will foul more quickly. Marine fish tend to be more sensitive to
this, and a larger aquarium is more forgiving to these complications. As a general rule- it I best to begin with a
rectangular tank for 45 to 55 gallons.
You should try to get a tank with the maximum surface area. So rather than a tall tank, go for a tank
with longer width and length.
It
is quite possible to utilize a small tank for a marine tank. But because of the rapid water quality
changes that may occur in a smaller tank, it is not recommended. Select the largest tank you can afford. This
is one of the most important decisions and will determine your future success.
Tank Shape
You
should also give careful consideration to the shape of your aquarium. The various available shapes have a direct
effect on the marine environment. Long
tanks provide greater surface area and reduced depth. The greater the surface area of the tank, the
better the gas exchanges at the surface- and therefore the more rapid the
dissipation of carbon dioxide and the absorption of oxygen. Certain aquarium shapes can appear pleasing
to the eye, but may not have the environmental advantages offered by more
standard designs.
As
a general rule- if two aquariums have the same gallonage, but differ in their
surface area. Always choose the greater surface area.
Aquarium Weight and Placement
A
very important consideration in deciding the size of an aquarium is its total
weight full. This includes water, pumps,
filters, and decorations like live rock, gravel, etc.
An
aquarium can be placed on a piece of furniture if it is capable of supporting
the weight. Keep in mind that saltwater
eventually will eventually spill on the surface of the furniture.
It
I most desirable to purchase an aquarium stand for your tank. It will support
the weight as well as resist any damage due to the corrosive nature of
saltwater.
You
must also be certain that the floor where the aquarium setup is placed can
support such a weight. For example- a
200-gallon tank filled with water, not including gravel, decorations, etc. will
weight 1700 pounds. Complete with decorations and gravel, this jumps to over 1
ton.
Setting Up the Aquarium
Once
you have purchased the basic equipment it is time to set up your aquarium.
Tank Location
Where
the aquarium is placed is a matter of personal preference. It makes a beautiful focus in a living room,
den, bedroom, or any other room. Larger
aquariums can be placed as an attractive room divider. Wherever you decide to situate the aquarium,
it is important to have easy access to multiple wall outlets to minimize the
use of extension cords.
The
aquarium should not be placed either in an area subject to cold drafts or in
one that is excessively warm. Do not
place the aquarium too close to a radiator, air conditioner, or directly in
front of a window hat receives direct sunlight.
While several hours of sunlight are beneficial to marine aquariums,
strong sunlight can promote excessive algae growth as well as overheating small
aquariums. This is particular dangerous
in the summer months.
The
selection of an aquarium and stand should also take into account the structural
integrity of the building or dwelling.
Always make sure the aquarium is level to avoid any stress on the walls
of the tank.
Substrate
The
substrate (material to cover bottom of aquarium) should be selected
carefully. Some bottom materials used in
freshwater aquariums are not suitable for use in marine aquariums. Freshwater aquariums often use quartz gravel,
epoxy covered rocks, or other dyed decorations.
These materials may become toxic with the interactions of seawater in a
marine aquarium.
Only
substrates with a calcareous composition should be used for marine
aquariums. These are the only types with
any ability to buffer the water. The most commonly available appropriate
substrate includes natural crushed corals, limestone, dolomite, or crushed
oystershell. A combination of these can
be used to create a natural habitat.
Aquarium
bottom materials are essential for proper biological and mechanical filtration
when an undergravel filter is used.
Large size grains of substrate should be avoided, as they inadequately
perform mechanical and biological filtration of the water. They also have
substantially reduced surface area compared to smaller size particles. This means there is less area for the
beneficial nitrifying bacteria to grow on.
On the other hand, very small grains, such as sand must never be used to
cover and undergravel filter bottom.
Sand will rapidly clog an undergravel filter and prevent uniform flow
though this plate. The general
recommendation is to select a grain size of 4 to 5 mm.
Various substrates are suitable for use in marine aquariums and
include a mixture of shells crushed coral and dolomite. Sand should never be used to cover the
aquarium bottom. Sand will rapidly clog undergravel filters and prevent a
uniform flow of water through the filter plate. The general recommendation is
to select a grain size of 3-5 millimeters (mm). If no undergravel filter is
used, virtually any size of calcareous material can be used to cover the
aquarium bottom.
Amount of Required
Substrate
The amount of material for an aquarium is mainly dependent on
whether you are using an undergravel filter. It is highly recommended that you
include an undergravel filter as standard equipment for your first aquarium.
With an undergravel filter recommended depth of bottom material is
2.5 to 3.0 inches (6.S-7.5 cm). This will ensure that you have ample material
for proper filtration through your biological filter. You may make the bottom
material deeper. But do not make it less that the stated guideline.
In aquariums without an undergravel filter, a shallow layer of
substrate is all that should be used to cover the bottom, with a depth of not
more than 1/2 to 1 inch (1.2-2 cm) of substrate. The size substrate in this
situation is not as critical as with aquariums with undergravel filtration.
Without an undergravel filter. The bottom material depth must be
restricted to minimize the possibility of anaerobic bacterial activity. These
bacteria develop in filter beds where there is restricted water flow to carry
dissolved oxygen.
Without a constant water flow through a filter bed, the substrate
favors the growth of anaerobic bacteria, producing toxic gases such as methane
and hydrogen sulfide. Both of these gases, even in very low concentrations, are
poisonous to marine animals.
Conditioning Water
Unconditioned municipal water is unsafe to use in an aquarium.
''Water conditioning" means different things depending on the context.
Here the phrase refers to the detoxifying of municipal water that contains
toxic chemicals, the most serious being chlorine and chloramine. Tap water can
also contain toxic metal ions such as copper, aluminum, or other dissolved
materials in concentrations that can be toxic to aquatic life. This can be a
particular concern in areas where water districts add copper to water
reservoirs during the summer to control algae.
All municipal water should
therefore be treated with a good-quality water conditioner prior to mixing with
sea salts. These conditioners are available as a liquid or powder. When used
according to instructions, they will destroy chlorine and chloramines within
minutes. Some conditioners will also render metallic ions nontoxic if they are
present in your tap water. Some brands of synthetic sea salts contain a water
conditioner that will destroy chlorine and chloramine while the sea salts are
dissolved. Water conditioners should al-ways be used whenever adding new tap
water to the aquarium.
Decorating Your Aquarium
The marine aquarium can be decorated or aquascaped in various ways
to simulate undersea habitats. You may decide to design a coral reef
environment. A reef and lagoon area, or a rocky deep-sea environment. It will
be helpful to obtain books or magazine articles with color photos of coral
reefs to become familiar with the appearance of the reef environment With such
photos as a guide you will be able to construct a more natural and
authentic-looking aquarium.
Coral and rock can be arranged to simulate a natural environment
and include ample hiding areas, ledges, and crevices for the aquarium fish.
Placement of the rock and coral should not be so complex that it
will be difficult to remove uneaten food or detritus during maintenance-
It is always best to start the arrangement of large pieces of
coral rock or other rock at the back of the aquarium. You can build up a wall
of rock, then place a few select pieces of coral on some of the ledges. Work
towards the front of the aquarium, arranging coral, rock, and decorations to
allow hiding areas, but also to leave ample swimming room for the fish.
Various types of natural decorations are avail-able to decorate a
marine aquarium, including several types of rock such as lava rock, coral rock.
There are also decorative items that are replicas of natural coral, sea fans,
gorgonian, and sponges.
Living macroalgae make beautiful additions to the marine aquarium;
in addition to being decorative they serve other purposes, including removal of
nitrogen compounds.
It is important to note that not all rock is safe for aquariums.
Many contain quantities of soluble metal salts that can quickly kill marine
animals. Only rock that has been purchased should be used in a marine aquarium.
Do not use any rock that has been collected unless you can be assured that it
is nontoxic. All rock should be washed well to remove any sand or dirt before
adding to your.
Natural Coral
The most frequently used decorative item in a marine aquarium is
coral. Various types are avail-able, including brain coral, finger coral
(Porites), staghorn coral, and organ pipe coral.
Any purchased coral should be soaked in fresh water prior to use
to ensure that all organic material has been cleaned before placement in the
aquarium. Coral from pet shops is often pretreated and cleaned prior to sale.
Such coral can be used after it has been rinsed to remove any dust or other
materials that have adhered to the coral skeleton.
However, it is still recommended that you subject it to a special
cleaning process. This ensures that all organic material has been removed from
the coral prior to placement in the aquarium.
First, the coral should be p]aced in a non-metallic bucket with
fresh water to completely cover the coral for at least 72 hours in a warm area.
If the water is still clear after 72 hours and no odor is
discerned, the coral can safely be re-moved, rinsed, and added to the aquarium.
However, if you notice a film on the water, a cloudy appearance to the water,
or a bad odor, remove the coral pieces, rinse well and proceed as follows.
Place the coral in a bucket using 8 ounces (0.2 L) of household
bleach for every gallon
Algae Growth in New
Aquariums:
Once your aquarium has been in operation for a week or more you will
undoubtedly begin to notice a brown color on the substrate, rock, and coral.
This process is quite normal and is the first stage in the
establishing of the aquarium. The brown color is primarily due to the Growth of
microscopic golden-brown algae called diatoms. Since they require very little
light to develop and are tolerant of various types of water conditions, they
are able to reproduce rapidly. However, if ample light of the correct intensity
is provided for at least eight to ten hours daily, you will notice the
development of green algae that will replace the growth of diatoms. This will
usually begin within several weeks to one month, and will first be noticeable
on rock or coral closest to the light source. With the correct conditions, the
green algae will slowly replace the brown algae and red algae, if they also
have grown during the first few weeks.
If growth of green algae does not begin within a month, the cause
may be inadequate light intensity or duration, water quality problems, and not enough
green algae cells to start the growing process. Green algae cells are usually
introduced with the fish or invertebrates. If the light and water quality
appear to be correct, it may be necessary to obtain a small culture of algae
from your retailer.
All that is needed is a small amount of green algae removed from a
rock or glass and placed in the aquarium.
WATER AND WATER QUALITY
Fish
and other marine organisms are directly influenced by the chemical, biological,
and physical characteristic of their environment. The water around coral reef habitats is
chemically stable because of the large volume of water, the constant currents,
wind, and other factors that help maintain the relative uniformity of the
oceans. As a result, reef organisms are
not subjected to wide fluctuations in the chemical and physical characteristics
of seawater. When there is a change- it is usually short
enough that the animals are not adversely affected.
The
situation in the aquarium is much different.
The aquarium water is not subject to constant renewals as in the
ocean. In contrast to a coral reef, the
aquarium water is subject to extensive alterations after the introduction of
marine organisms. The alteration of water quality is due to the buildup of
chemicals that originate from various biochemical processes, most notably the
metabolic activities if fish, invertebrates and algae. If these chemicals are permitted to
accumulate to concentrations beyond which aquatic animals can tolerate , the
survival of the animals is in jeopardy.
The toxicity of many of these compounds is such, that even short
exposure to low concentrations may be lethal.
That is why it is so crucial to test water regularly and perform
periodic water changes.
Natural Seawater
Seawater
is a complex medium of numerous chemical compounds, both organic and
inorganic. Sodium Chloride, is the most
abundant element in seawater. This is
the same as common table salt. he other
major components are magnesium chloride, magnesium sulfate, and calcium carbonate. In smaller concentrations, other trace
elements are present. Some of these
include molybdenum, selenium, cesium, vanadium, zinc, iodide, and iron. Though these elements are low in
concentration, they are required for the biological processes of many plan and
animals organisms.
Marine
aquariums can be filled with either natural seawater or freshwater plus a
synthetic seawater mixture. Natural
seawater must first go through a conditioning process before being used in your
aquarium. Natural seawater contains many
planktonic organisms. Most of these are
microscopic. These are both plant
(phytoplankton) and animal(zooplankton).
If the water is not properly conditioned, then the death of these
organisms could cause radical changes to the water quality. Secondly, naturally collected seawater is a
vector for disease. Many parasites, and
diseases may be introduced, as well as planktonic forms of animals that are
potentially harmful. For the new
aquarist, it is far easier to use synthetic seasalt.
If
you do collect natural seawater, then it should be collected away from inshore
areas, or inner bays. This is to ensure
the best water quality and least amount of urban pollution and runoff. Nearshore areas can be polluted by from
fertilizer runoff, sewage, toxic metals, insecticides, and other
pollutants. Inshore waters may also
contain a high level of suspended particles, mostly from storm drain run off,
and erosion from shoreside developments.
And even freshwater rivers flowing into the ocean. Collect all seawater
in non-toxic plastic containers with secure lids. Once collected, you should leave the
containers in a dark room, with the lid on for 3 weeks. This allows any harmful organisms to die off
and the toxins to dissipate. After
storage, you will notice a layer of detritus from the dead microorganisms on
the bottom. This should not be added to
the aquarium. Instead, siphon off the
top layers of water and add to aquarium.
After addition to the aquarium, you should always monitor pH, ammonia,
nitrite, and nitrate, and increase aeration to disperse new water evenly.
Synthetic Seawater.
The
invention of synthetic sea salt mix for keeping marine fish and invertebrates
in aquariums was a major achievement that enabled anyone anywhere to set up a
marine aquarium. It allowed the
convenience of preparing seawater by mixing synthetic sea salt with a
freshwater source. There are many formulas available today that are of very
high quality and mach natural seawater very closely. Experience has demonstrated that these
synthetic seasalts can be a superior choice for supporting life.
The
major advantages of preparing synthetic sea water are that it is free of
pollutants and microorganisms that could transmit disease or foul the water,
there is no need for storage for extra seawater, and the preparation can be
used a short time after mixing.
Various
commercial mixes are available for making seawater.. The salt is simply mixed with an appropriate
amount of tap, DI, or RO water, allowed to mix until thoroughly dissolved, and
then salinity adjusted until at appropriate level. Using this method, fish can be introduced
into a new aquarium in as little as 12 hours.
Water Parameters
Once
the fish are introduced to the aquarium water, it will begin to undergo a
series of chemical changes, not all of, which are conducive to the support of
aquatic life. It is therefore crucial to
ensure that a high quality of water quality is maintained. Marine animals are extremely sensitive to
water deterioration and are not as tolerant as many species of freshwater fish
to poor water quality. Without a
thorough understanding of the required water quality parameters you will not
succeed as a saltwater aquarist. There
are a number of parameters that are critical.
Temperature
Most
aquarists will be stocking their aquariums with fish and invertebrates from
coral reef habitats. Living coral, and
other invertebrates, and fish are extremely sensitive to rapid temperature
fluctuations. Since fish and inverts are
cold blooded, they are directly affected by temperature, which affects their
activity, feeding behavior and immunity and other metabolic functions. For example, the higher the temperature, the
greater the need for food.; but this causes an increase in the metabolic waste
products in the water. If there is too
low a temperature, the activity levels of the animals slows, and a reduction in
growth rate, and sensitive animals like corals will die. Such problems, especially the buildup of
wastes, are inconsequential on the coral reef, but are deadly within an
aquarium.
Temperature
also affects the amount of dissolved gases that directly affect the marine
organisms. At high temperature, less
oxygen will dissolve in water. This
reduces the capacity of the aquarium and the waters ability to provide oxygen
to the fishes respiratory system.
The
temperature of an aquarium should be constant and maintained within an
acceptable range. The ideal range for many marine animals is 77 to 82 ˚F
(25-28˚C). This range takes into account
the majority of marine animals that would be kept in an aquarium. However for
the majority of aquariums stocked only with fish, the recommended range would
be 77 to 79 ˚F (25-26˚C). Certain
animals will require either a lower temperature or a higher one. It is always best to research any specimen
before introducing it into an aquarium.
pH
The
pH of water is a measure of acidity or alkalinity. The pH ranges from 0 to 14, with 7 being a
neutral point. Above neutral, pH 7,
water is alkaline,. Below pH7, water is
acidic. Because of the complex chemistry
within an aquarium, the pH may undergo major shifts.
In
nature, the pH of ocean water is usually 8.0 or above, varying with the
locality. It is recommended that
seawater in the marine aquarium be maintained within the range of 7.8 to 8.3,
depending on the type of marine organisms maintained. A pH of 8.0 to 8.3 is the generally accepted
value for an aquarium with both invertebrates and fish.
Changes
in the pH of the water are caused by various chemical reactions and the
presence of chemical compounds that slowly accumulate. Several factors in an aquarium contribute t
changes in pH, including the nitrification process, the concentration of carbon
dioxide and the amount of natural buffers.
The
nitrification process releases acids that react with bicarbonates to neutralize
the acids. Without bicarbonates and
carbonates to buffer the water, it would slowly become acidic, endangering the
animals. Buffers restrict a great change
in the pH of a solution. Water in the
ocean, which is naturally buffered, has great pH stability. Many synthetic seawaters contain sufficient
buffers for the new aquarium. The type
and quantity of substrate can also play a role in maintaining the pH of a
captive marine system. Carbon dioxide is
also a source of acid in an aquarium.
Aquariums with inadequate circulation and aeration can buildup excessive
amounts of carbon dioxide.
The
general trend of pH in a stocked aquarium is a continual decrease towards more
acidity. Gradual declines are not
harmful, but the marine hobbyist must be aware of pH changes to ensure that it
does not fall outside of the acceptable range.
Various types of substrates will help to buffer the water and maintain
the pH. However, one time use compounds
will become exhausted and have to be replaced.
The
pH of water can be measured with inexpensive kits. A few drops of an indicator chemical is added
to a sample of aquarium water in a test vial.
The color of the sample is compared to a color chart that indicates the
pH of the water. This test should be run
weekly for established aquariums, and every day for new aquariums. A pH kit is essential for any aquarium.
Dissolved Oxygen
Aquatic
marine mammals in nature inhabit an environment with an abundance of dissolved
oxygen. In aquariums equipped with
proper filtration and aeration, sufficiency of dissolved oxygen is seldom a
problem. It is therefore generally
unnecessary to test oxygen levels on
regular basis in an aquarium.
However, it must be understood that as the temperature of an aquarium
increases, the levels of dissolved oxygen in the water decrease.
Ample
concentration of dissolved oxygen is also required for the normal function of
the biological filter bed bacteria. The
nitrifying filter bacteria are a major consumer of dissolved oxygen in an
aquarium. In general, it is recommended
that dissolved oxygen saturation e at near saturation levels. To avoid a low DO problem, avoid
overcrowding, overfeeding, and overcrowding situations.
Specific Gravity and Salinity
The
specific gravity (density) is the ratio of the amount of total dissolved solids
water when compared to pure water. Pure
water has a specific gravity of 1.000.
As more salts are added to this volume, the specific gravity increases.
The
amount of salt in a marine aquarium is determined by the use of a hydrometer. This instrument is made of a sealed glass
tube with an internal scale. The
hydrometer is weighted at the base and floats freely when placed in the water.
Higher quality hydrometers are calibrated to seawater at a known temperature,
usually 59˚F (17˚C. If a reading is taken at any temperature other than 59˚F
(17˚C), the reading must be corrected by a table using a table of conversion
factors. Such tables also give the salinity values. The temperature must be taken into account,
as seawater expands and becomes less dense as temperature rises.
Other
hydrometers are available that are standardized at different temperatures and
are more appropriate for the use in marine aquariums. A correction I not
required since they have been calibrated for the ideal temperature range for
fish and invertebrates. Another variety
of hydrometer is constructed from a narrow plastic chamber and it has a
dial. A water sample is collected and
fills the chamber and the dial indicates the specific gravity. When used according to instructions, a
correction table is not necessary. This
is the easiest method to test specific gravity in your aquarium.
Marine
aquarists can determine the correct density (specific Gravity) by use of a
hydrometer that has been calibrated for use in a marine aquarium. Two methods are suggested: (1) Reading in the
aquarium. Turn off the filters and
aeration devices to prevent movement.
Then carefully place the hydrometer into the aquarium and wait until the
vertical movement stops. Read the scale
at the lowest point where the water level crosses the hydrometer scale. Record times, date and temperature along with
your density observation. (2) Fill a clear cylinder with a water
sample. Carefully place hydrometer into
sample and wait until all vertical movement is stopped. Read the scale as indicated above. Record vales.
Fish
and invertebrates should be maintained in water with a specific gravity of
1.020 to 1.024 at temperatures of 77 to 80˚F (25-26˚C).
Specific
Gravity checks should be conducted every week or two. As water evaporates, the specific gravity
will increase, requiring replacement with conditioned tap water. If the specific gravity drops below the
normal range, you will need to add small amounts of seasalts. This must be done with caution, as to avoid a
rapid change in salinity.
Nitrogen Compounds
Various
nitrogen compounds formed in the marine aquarium are generated from biochemical
processes including the breakdown of proteins and waste products from marine
animals The principal nitrogen products
of concern to the marine hobbyist are: ammonia, nitrite, and nitrate.
Ammonia
Ammonia
is the most toxic product formed in water.
It originates from the decomposition of nitrogen-containing organics
such as plans and food. Sources for
ammonia in the aquarium are the fish, other organisms, and decaying food.
Ammonia
exists in two chemical forms in water; an unionized form (NH3) and an ionized
form (NH4+). The combination of these two forms termed total ammonia. Both exist in water, but the proportion of
each type is dependent on the pH, temperature, and other factors. The unionized form is extremely toxic to
marine animals, both fish and invertebrates.
The higher the pH, the higher the concentration of unionized ammonia.
Chronic
concentrations of ammonia in aquariums indicate that there is a serious problem
that can be related to various factors, including overcrowding, filter
malfunction, or overfeeding. Fully
functional and operational aquariums should have no detectable traces of
ammonia.
Ammonia
can be easily detected using commercially available test kits. Some kits will express the results as ion,
while others will express it as ammonia-nitrogen. As a general recommendation,
the unionized form of ammonia must not exceed 0.01 mg/l in marine aquariums. Always follow the manufacturer’s instructions
exactly to obtain the correct readings for ammonia.
Nitrite
During
development of nitrifying bacteria in the filter bed, the bacteria will
transform ammonia into another form of nitrogen called nitrite. Nitrite is an intermediate step in the
nitrogen pathway in the conversion of ammonia into nitrate. The highest concentrations occur during the
initial establishment of the filter bed.
Once the bio-filter has been established, it is often impossible to
detect levels of nitrite. Though nitrite
is less toxic than ammonia, it is still toxic to marine organisms. This is
because it binds with blood cells, which will prevent the normal uptake of
dissolved oxygen.
Nitrate
Nitrate
is formed from the chemical conversion of nitrite in the marine aquarium. It is far less toxic than nitrite and
ammonia. Recent research has shown that
nitrate is harmful to marine invertebrates, and may contribute to poor health
among fishes. In fishes, long term exposure
to levels of nitrate will impair growth, and longhorn survival.
It
is recommended that nitrate not exceed 10 mg/L(ppm), and preferably should not
exceed 5mg/l (ppm) for invertebrates.
The lower levels can often be difficult to obtain in many aquarium
systems.
Nitrogen Pathway.
A
new fish tank is a sterile environment.
It has no beneficial bacteria, and nor harmful bacteria. No animal wastes, no decaying food, etc.
As
wet set up the aquarium, we slowly introduce these facets into the
formula. A freshwater fish produces
ammonia (NH3) as its primary nitrogenous waste product. This ammonia is excreted via the gills and
the fishes urine. The fish also excretes
solid wastes via feces.
Ammonia,
NH3 is toxic to fish. It can cause
surface burns to their skin, and causes respiratory complication. It is also able to ionize into NH4+, or
ammonium. Ammonium occurs in highest
quantities in a tank with a pH over 7.0.
In a pH less than 7.0 the levels of ammonium re reduced. But the ammonia
is still there!
This
ammonia will build up to toxic levels unless it is removed. That is where our filtration comes in. We aid in the removal of ammonia via the
different methods of filtration.
Chemical filtration, is a carbon filter or an ion exchange resin filter
(like Chemipure). This kind of filter
removes many of the dissolved organics from the water. A biological filter is one that supports
growth of bacteria that break down some of the fish wastes, These bio-filters usually have a material
that allows millions of microscopic
bacteria to flourish. These bacteria
oxidize and convert the ammonia and ammonium into nitrite. These bacteria are called Nitrosomonas.
Nitrite,
NO3 is also toxic to fish. In very small
concentrations it will cause respiratory
distress and make fish susceptible to invading disease. Nitrobacter bacteria
consume this nitrite. They convert it
into Nitrate. NO4.
Nitrate
is relatively harmless to freshwater fish in normal concentrations. There are no bacteria in standard freshwater
aquarium set ups that convert nitrate into anything else. So it must be removed in some manner.
The
most common way to remove nitrate is through regular partial water
changes. This physically removes the
nitrates from the water. This also has
the additional benefit of replenishing many of the nutrients and minerals taken
up by plants ands animals.
Some
common experiences of new fish keepers include problems associated with this
Nitrogen Pathway.
Commonly
referred to as the ‘Nitrogen Cycle’, the Nitrogen pathway is really not a
cycle, but a line. The fish produce
ammonia, Nitrosomas convert it into Nitrite.
Nitrobacter converts the Nitrite into Nitrate and we end up with
Nitrate. The fish don’t utilize nitrate,
so it's not a true cycle.
In
a new tank we are lacking established populations of Nitrobacter and Nitrosomas
bacteria. We put in our new fish and
they produce ammonia. But instead of the
conversion to nitrite, it sits. And
kills the fish. In many new tanks, you
will see a white haze in the tank. This
is accumulated ammonia in solution. It
has yet to be removed/converted by bacteria.
Because our new tank is sterile, it does not have any living bacteria to
help with this. We solve this problem in
three ways. 1) Do nothing. Not the best as it puts those first few hardy
fish under tremendous stress of high ammonia, and then high nitrite
levels. All fish carry these same
bacteria in their intestines and mouths, so some will eventually fined there
way to the filter and grow. But you can
have deadly spikes in ammonia and nitrite and heavy fish loss. 2) Supplement
with a commercial bacterial product. I
like to do this. There has yet to be a
miracle product that does it all, so don’t believe the ads. But it does make it less rough on the fish
and helps speed things up bit. All told, it takes about 21 to 28 days for
this to occur. A bit less with a bacterial supplement. 3) Is to introduced a seeded filter bed. This is ideal, as you have a working filter
material with millions of living
bacteria. This is the best method as it reduces the wait to just a few hours. Its a shame more pet stores don’t offer this
as a service to the customers, as it would allow many more fish success and
bring back return customers again and again.
High Ammonia
If
you have a high level of ammonia in your tank it is a sign of 1) a new tank, 2
overfeeding, 3) recent use of medication 4) filter malfunction 5)
overcrowding. Some of these problems can
be prevented, others can be eliminated altogether.
If
you have a high ammonia level, you need
to do a partial water change right now!
Do a 50% now. If your ammonia is
4.0 PPM and you change 50% of the water, you will end up with a 2.0 PPM, still
deadly on the scale. But you don’t want
to risk shocking the fish with temperature of pH, etc. too much, so start with
a 50% water change.
Next,
evaluate your pH. Actions or
circumstances that cause a decrease in pH cause Many times a rise in
ammonia. If it's 6.5 to 7.0 just monitor
it. It's not too low to be a problem to
any fish except marine fish and some African cichlids. If its above 7.0 we have to be even more
concerned Ammonia become ammonium (NH4+)
at pH over 7.0 And Ammonium is even more
toxic than ammonia (NH4). If the pH is
above 7.0 then you should try to adjust it slowly back to 7.0 with the 50%
water change you are working on.
Next
we have to evaluate why the high ammonia exists. Is it a new tank? If so, then you have a problem with ‘New Tank
Syndrome”. This is because a new tank is
relatively sterile and does not yet contain the beneficial bacteria to
breakdown fish wastes and convert them to less toxic materials. If this is the case, you need to hold off on
any new fish and see if you cab help the process along with a commercial
supplement or a seeded filter.
Is
the tan overcrowded? How do tell if the
tank is overcrowded? Well, typically,
you can assume 1 gallon of water per inch on fish in any direction. That means a Neon Tetra needs on gallon. A 3-inch Angelfish needs 3 gallons for its
length, plus another 3 for its height., for a total of 6 gallons. This is a rule, and there are always
exceptions. One noteworthy exception is
the goldfish. They are exceptionally
messy fish. They like even more space,
along the lines of 5 gallons per inch.
That means that cute 1-inch goldfish needs a 10-gallon filtered aquarium
gallon to thrive! If you determine the
tank is overcrowded you have a few
options. You can see if your local fish store will take back a few of the extras, or see if
another fish keeper will take them for you, or you can get a larger tank. It's a common mistake that adding another
filter to a smaller tank will help. For
a quick and temporary fix, it will,. But
fish need space too, and this does not provide them the space they need.
The
increase in ammonia may also be from recent use of medication. Most medications
are antibiotics, designed to kill bacteria that infect out fishes. The
beneficial bacteria that breakdown the ammonia are also a type of
bacteria. Many of the medications used
to treat fish will actually harm the ‘good guys’ as well. This is why it's best to treat fish in a
separate tank. If you have recently
treated the tank, then you consider the problem to be the same as if you had a
brand new tank.
Filter
malfunction can also cause a rise in ammonia.
If the filter stops filtering because of mechanical malfunction, then
the water builds up the ammonia. Regular
inspection of the intakes, hoses, motors and impellers if your filter has one
is recommend to prevent this from occurring to you. The other possible problem with filters is clogging. All filters have some sort of insert for
mechanical filtration. Many items this
is a sleeve or sponge of foam of floss.
This needs to be rinsed and checked about once per week to keep it clean
and free from debris. If it's less than 3 weeks old and it brown and
smelly, then you have a classic case of overfeeding.
And
overfeeding is the next cause of an increase of ammonia. If you feed your fish too much, the excess
wastes become ammonia because of the normal fish metabolism. Think about it. Fish in a tank have a simple existence. The temperature is controlled, there are no
predators to run from (we hope you have selected compatible fish) and all food
is provided. So there energy
requirements are less than that of the fish migrating up river. It is best to feed our aquarium pets a few
SMALL meals daily. That means just a few
flakes or pets two to three times a day.
Don’t worry if everyone doesn’t get some. The ones who miss a meal in the morning will
be first in line for the evening meal!
So
now you know why you have an increase and you have performed that first 50%
water change. You now have stop feeding
for 24 hours and re-test. In 24 hours do
another 50% water change and re-test.
You should notice an improvement.
FILTRATION TYPES
Why you need Filtration
Sometimes
we forget that fish kept in an aquarium are confined to a very small quantity
of water as compared to their natural habitats in
the
wild. In the wild, fish wastes are instantly diluted. But in an
aquarium,
waste products can quickly build up to toxic levels.
These
waste products include ammonia released from your fishes' gills,
fish
poop, and scraps of uneaten food. The food and the poop will also
eventually
decay, releasing ammonia. Even small amounts of ammonia
will
kill your fish.
Obviously,
the more sources of fish waste, the quicker and greater the
ammonia
problem. A small heavily fed tank with lots of large fish will
have
much more ammonia than a large tank with one seldom-fed small
fish.
But for both these cases you need some form of aquarium
filtration
to control the toxic ammonia.
Some
aquarists try to control ammonia levels exclusively by changing
the
water. This is helpful, but impractical because of the frequency
and
size of the water changes required.
Fortunately,
there is an easier way! In fact, the world is full of
bacteria
that want nothing more than to consume the ammonia and
convert
it into less toxic substances. For many an aquarist, this
process
occurs without their knowledge or help. However, the smart
aquarist
will learn how to take advantage of this beneficial bacteria
by
maximizing its growth.
When
you start a new fish tank, colonies of beneficial bacteria have
not
yet had the chance to grow. For a period of several weeks this is
hazardous
to fish. You must gradually build up the source of ammonia
(i.e.,
start with only one or two small fish) to allow time for the
beneficial
bacteria to grow. This is called ``cycling'' your tank.
Remember
that the bacteria break down the ammonia into substances
(first nitrate, then eventually nitrate) that
are merely less toxic,
rather
than non-toxic. Many fish can tolerate reasonably high levels
of
nitrates, but over time the nitrates will accumulate until they,
too,
become toxic. Also, because nitrate is a fertilizer, high nitrate
levels
can lead to excess algae growth.
WATER CHANGES
Although
there are many ways to remove excess nitrate, the most
effective
way is to regularly change part of the water. This is one of
the
most neglected and important parts of aquarium maintenance!
How
often and how much you need to change depends a lot on the waste
load
in your tank, and the sensitivity of your fish. You don't want to change ALL of
the water at any point in time because the change in water chemistry will be
stressful to your fish. The best way to decide how often and how much to change
your water is to monitor your water quality with water tests. As a minimum, if
your tank is new, you should test for ammonia and perhaps nitrite. In
established tanks you should monitor for nitrate accumulation. Water tests are
the most reliable way to know how well your aquarium filtration works.
For
an average tank, you should change no more than one third of the water in 24
hours. Many aquarists with average aquariums change a quarter of the water
every two weeks. Your aquarium is probably not average, and you really should
measure nitrate levels to determine your water change schedule.
BIOLOGICAL
FILTRATION
Biological filtration is the term for
fostering ammonia neutralizing
bacteria growth. It is so important to the
health of your aquarium
that we should look at how this process
works more closely. (There are
other types of wastes that can cause
problems, but the regular partial
water changes needed to control nitrates are
typically enough to
control other forms of waste as well.)
Mother Nature provides several types of
bacteria that break down
ammonia into progressively less toxic
compounds. First, nitrosomonas
breaks ammonia into nitrites. Then
nitrobacter breaks the nitrite into
nitrate. These bacteria are not harmful and
are quite abundant in
nature. They are so common that we do not
need to add them to our
aquariums; nature does it for us.
In the presence of ammonia and oxygen these
bacteria will naturally
multiply. The bacteria attach to the tank,
rocks, gravel, and even
tank decorations. Note that we have not yet
said anything about a
physical filter. This is because
biofiltration bacteria require only
1. A surface upon which to attach,
2. ammonia for food, and
3. oxygen-rich water.
This sounds so simple; why do we need a
physical filter?
Actually, if you limit the amount of fish to
what the natural
biofiltration can handle, you do not need a
physical filter.
Unfortunately, you cannot support very many
fish with only the natural
biofiltration.
In the last few decades, the hobby has seen
many new types of
biological filters invented which can vastly
increase the capacity of
the bacteria colony to provide biological
filtration to your aquarium.
In essence, all of these types of filters
provide additional surface
area for bacteria attachment and increase
the available oxygen
dissolved in the water.
MECHANICAL
FILTRATION
Remember that ammonia comes directly from
the gills of your fish, but
also from decaying fish poop and food
scraps. If you can mechanically
filter out the poop and the waste food
before it gets a chance to
decay, you can be a step ahead in the game.
Not to mention that these
wastes are ugly and can detract from the
beauty and enjoyment of your
aquarium.
Simply stated, mechanical filtration is the
straining of solid
particles from the aquarium water.
Mechanical filtration does not
directly remove dissolved ammonia. Most
common mechanical filter media
do not remove microscopic bacteria and algae
from the water. Neither
will mechanical filtration remove any solids
trapped by gravel,
plants, or decorations.
You will need another method to remove the
solid wastes from the nooks
and crannies of your aquarium. One of the
easiest methods is to
``vacuum'' the gravel, etc., as part of your
regular water change
routine and everybody should do this. (Note
that those marine
aquariums, which use live substrates, are an
exception.) Some people
install circulation pumps, known as wave
makers, to improve the chance
of catching solid wastes in the mechanical
filter.
The four most popular mechanical filtration
media are sponges, paper
cartridges, loose and bonded floss media,
which are reusable to
different degrees. Clean paper cartridges
have the smallest openings
and clean bonded floss has the largest
openings. Clean sponges and
clean loose floss falls somewhere between.
A filter media with small openings catches
finer particles, but clogs
faster. Also, as a rule, a physically large
filter area will clog more
slowly than a small filter. As the filter
media gets dirty it will
trap smaller and smaller particles. At some
point the media is so
clogged that it will not pass water.
SUMMARY: A good mechanical filter is one
that traps enough solids to
keep the water clear without plugging too often.
CHEMICAL FILTRATION
Chemical filtration, in short, is the
removal of dissolved wastes from
aquarium water. Dissolved wastes exist in
the water at a molecular
level, and fall into two general categories,
polar and nonpolar. The
most common chemical filtration method
involves filtering the water
through gas activated carbon which works
best on the nonpolar wastes
(but also removes polar wastes). Another
effective method is protein
skimming, which removes polar wastes such as
dissolved organics.
Gas activated carbon (GAC) is manufactured
from carbon, typically
coal, heated in the presence of steam at
very high heat. This process
causes the carbon to develop huge numbers of
tiny pores, which trap
nonpolar wastes at the molecular levels by
means of adsorption and ion
exchange, and removes heavy metals and
organic molecules, which are
the source of undesirable colors and odors,
through a process known as
molecular sieving. Be sure that when you
place GAC in your filter,
that the filter water flows
"through" the GAC granules and not
"around" the GAC.
Most GAC, which is marketed to the aquarium
market, is intended for use
in filtering aquarium water, except coconut
shell GAC which is
intended for use in the removal of wastes
(such as odors) from air.
In reef aquariums, some people are concerned
about phosphate leaching
from low quality carbons, though there are
mixed opinions on the
problem. As a rule, buy only carbons made by
reputable aquarium supply
companies, and if in doubt, test the GAC for
phosphate before use. GAC
cannot be rejuvenated.
In freshwater-planted aquaria, some people
are concerned about GAC
removing trace elements required by plants
for healthy growth.
A variety of special chemical filtration
media have been developed to
remove specific chemicals. A common one is
made from the zeolite clay
(also used as some cat litters), and is
marketed under such brand
names as ``Ammo-Carb''. This media removes
ammonia from water, and is
good for short term use. The aquarist should
be aware that if zeolite
is used, especially when cycling a new
aquarium, then the
establishment of natural biological
filtration will be delayed or
disrupted.
Protein skimmers are primarily used in
saltwater aquaria, especially
reefs. They have the remarkable ability to
remove dissolved organic
wastes before they decompose. The process
involves taking advantage of
the polar nature of the organic molecules,
which are attracted to the
surface of air bubbles injected into a
column of water. The resultant
foam is skimmed off and discarded.
FILTER TYPES
THE
CORNER FILTER
For decades, hobbyists have successfully
kept fish healthy and happy
through the use of the $2.49 corner filter.
Typically, they are clear
plastic boxes, which sit inside the tank. An
air stone bubbles air
through an air lift tube, which forces water
through a bed of filter
floss or other media. mechanically filtering
the water. Colonies of
bacteria build up on the media, providing
excellent biological
filtration. (It is important to change only
some of the media at any
given time! This way the bacteria does not
get wiped out.) Nowadays
people don't use corner filters as much
because they're ugly, take up
space in the tank, and require a bit more
frequent maintenance than
other filters. But you can't beat the price.
Another use of the corner filter, that is
not really matched by other
filter types, is as an impromptu quarantine
tank filter. If you have
the need to set up a second tank on the
quick, you can take some
gravel from an established tank and put it
in a corner filter, and
immediately, you will have a functioning
biological filter. This way
you can turn a five gallon bucket into a
quick and cheap
hospital/quarantine tank on a moment's
notice.
UNDERGRAVEL
FILTERS
Fish stores commonly sell undergravel
filters (UGF's) to beginners in
``aquarium kits'' because they are cheap,
and they work (for a while).
They work by slowly passing water through
the bottom gravel, which
sits on top of a perforated plate. The water
can be pumped with an air
lift, with bubbles air lifting the water in
a vertical tube attached
to the filter plate. Also, some people
prefer the increased water flow
achieved with submersible pumps, called
powerheads, attached to the
same lift tubes.
UGF's make good biological filters, because
the slow flow of water
through the gravel fosters large colonies of
beneficial bacteria which
neutralize toxic ammonia. The hitch is, that
UGF's are awful
mechanical filters. Fish waste gets pulled
out of sight into the
gravel. Before you know it, the gravel clogs
up. You then have a big
mess and a health risk to your fish!
A partial solution to this dilemma is to run
the powerhead in reverse,
sending water up through the gravel. This
technique is known as
Reverse-flow Undergravel Filtration (RUGF);
conversion kits or
special powerheads can be purchased to
accomplish this. The intake of
the powerhead is covered with a porous
sponge which serves to
"prefilter" out some of the waste
that can clog the gravel. In
actually practice, this helps, but is only a
partial solution.
If you choose to use an UGF/RUGF, you must
regularly vacuum your
gravel. Fish stores sell siphon hoses with a
``wide mouth gravel
vacuum tube'' attachment that ``washes'' the
gravel during your
regular water changes. IF you clean your
gravel regularly, and
maintain a regular and frequent partial
water routine, UGF's and
RUGF's are an economical and effective
aquarium filter in freshwater
aquariums, and in lightly stocked saltwater
fish-only aquariums.
SPONGE
FILTERS
Sponge filters provide an efficient and
cheap form of biological
filtration. Water is forced through a porous
foam, either by a
powerhead, or air bubbling through an
airlift tube. Water flowing
though the sponge allows the growth of a
colony of beneficial bacteria
which neutralizes toxic ammonia.
One style of sponge filter uses two sponges
attached to one lift tube.
These have the advantage that the sponges
can be cleaned one at a
time, reducing bacterial loss. Also, one of
the sponges can be removed
and transferred to a new tank, bringing with
it a colony of beneficial
bacteria, and thereby "jump
starting" the cycling of a new tank. Some
enlightened fish stores sell these double
sponge filters to beginner
customers when they sell a tank kit. They
take one of the new sponges
out of the "box" and swap it for a
old established sponge in one of
their tanks in their store which is carried
home in a plastic bag.
POWER FILTERS
Most
people agree that power filters are much easier to maintain and
can be as economical as undergravel filters.
There are many styles of
power filters, but the most common hangs on
the back of the tank. A
siphon tube pulls water from the tank into
the filter box and passes
the water though a mechanical filter
(typically a porous foam sponge).
The sponge doubles as a biological filter. A
internal pump then
returns the filtered water into the
aquarium. These power filters come
in many sizes suited for small to large
aquariums.
The foam sponge can be easily inspected for
clogging or removed for
cleaning. You must clean the sponge
regularly to remove the solid
wastes before they decompose and dissolve
back into the water. It is
quite important that when you clean the
porous foam that you do not
kill the bacteria colony through the use of
detergents, very hot or
very cold water. A safe and easy way is to
rinse the foam sponge in
the bucket into which you have just drained
some tank water during
your regular water change routine.
Power filters now come with all sorts of
fancy ``features''. Most
allow placement of a chemical filtering
media, typically granular
activated carbon, in the water path.
Another development in the last few years is the ``wet-dry wheel''
(called a biowheel by one manufacturer). The
beneficial bacterial
colonies that neutralize toxic ammonia
require an oxygen rich
environment to grow. The ``wet-dry wheel''
passes water over a water
wheel device which sits outside (on the
edge) of the aquarium. This
rotating wheel maximizes available oxygen
allowing a large bacteria
colony to flourish. One drawback is that
these wheels have been known
to jam, so you need to check them
frequently. Other than this minor
point, the ``wet-dry wheel'' is an excellent
method of providing
vigorous biological filtration.
THE
CANISTER FILTER
Canister filters have some similarities with
the ``hang on tank''
style of power filters, but the essential
difference is that canister
filters are designed to provide more
powerful mechanical filtration.
Typically, the water is pumped, at moderate
pressure through a filter
material, such as glass wool, or a micron
filter cartridge. Canister
filters are especially useful in aquaria
with large or numerous messy
eaters that generate a lot of waste. For
these filters to be effective
they must be frequently cleaned, to avoid
the decomposition of waste
in the water stream.
These filters usually sit on the floor below
the tank, but also can
hang on the tank, and in some designs even
sit inside the tank, in
which case they are called a ``submersible
filter''. Some hobbyists
attach a ``wet-dry wheel'' to the outflow of
their canister to improve
the biological filtration capacity of this
type of filtration system.
WET/DRY
FILTERS
Also known as trickle filters, wet/dry
filters work on the principle
that the beneficial colonies of ammonia
neutralizing bacteria grow
best in the presence of well oxygenated
water. By ``trickling'' water
over unsubmerged plastic gizmos or other
media, wet/dry filters
provide a very large air/water surface area.
They come in many shapes
and sizes. The boom in successful saltwater
aquariums in the 1980's
can be attributed to the use of this filter
type.
Many things can used for the media, with the
best providing great
amounts of surface area, while at the same
time having large openings
to reduce the tendency to clog and ensure
efficient gas exchange. The
problem of clogging of the media can also be
reduced by prefiltering
the water with an efficient mechanical
filter, and (when used) with a
protein skimmer.
PROTEIN SKIMMERS (AKA FOAM FRACTIONATORS)
Protein skimmers were initially developed
for use in industrial sewage
treatment plants where they are also known
by the term foam
fractionator. Protein skimmers have the
unique ability to remove
dissolved organic wastes BEFORE they
decompose! This is a neat trick
which is accomplished by taking advantage of
the fact that organic
chemicals are attracted to the surfaces of
bubbles, which are passed in
large numbers through a column of water. The
foam is then ``skimmed''
off the water, while at the same time
removing the organic wastes. The
foaming process only works in a water with
high pH and salinity, and
as a result skimmers are primarily for
saltwater use.
The protein skimmer is largely responsible
for the boom in reef
aquaria in the 1990's, due to the high water
quality possible with
this type of filtration. A current ``state
of the art'' in reef
systems is based upon the use of protein
skimmers and live rock
without the use of a wet/dry filter. This
school of thought is known
as the ``Berlin method''.
FLUIDIZED BED FILTERS
Very recently, some hobbyists have reported
success with a new type of
filter which uses a fluidized bed of sand.
This filter is roughly
similar in principle to the reverse flow
undergravel filter, but with
much higher water flow. The higher water
flow keeps the sand clean of
debris, while at the same time allowing the
development of large and
efficient colonies of beneficial bacteria.
Reported problems include
oxygen depletion and clogging.
DENITRATORS
Another specialized type of filter is
designed to help in the control
of the accumulation of nitrates, the end
product of the neutralization
of ammonia by the biological activity of
bacteria. These fall into two
categories, the anoxic bacterial, and the
plant/algal scrubbers
(discussed in the next section). It has been
discovered that colonies
of bacteria which grow in oxygen poor
environments can be harnessed to
biologically consume nitrate, and release
harmless nitrogen gas. This
method is achieved in one of two ways. The
process was first developed
in the 1980's through the use of a box
system, coil, or porous foam
block which allowed very slow transmission
of nitrate-laden water.
Inside the box/coil/foam, sugar was placed,
and the slow passage of
water quickly became anoxic. In these anoxic
conditions, bacteria
would grow and consume excess nitrate. Many
aquarists have reported
failure in their attempts at this type of
filtration.
More recently, hobbyists have developed
similar anoxic conditions
below plates at the bottom of their tanks
buried in fine sand. In the
saltwater systems, these sand beds are
referred to as "live sand". In
freshwater planted systems, fine grain
substrates are allowed to
develop anoxic zones which probably also
have a denitrification
capability.
The Berlin Method of reef aquariums involves
the use of large
quantities of live rock harvested from
tropical reefs. Aquarists
report good nitrate control in live rock
systems, which, though not
well understood, probably involves the
denitrification of the nitrates
within the interior of the rocks. Another
school of thought is that
the heavy growths of calcareous algae on the
live rocks in Berlin
Method reef aquariums consume nitrate.
ALGAL
SCRUBBERS
Algal scrubbers use live algae to do the
“filtration''. Water is run
over a wire mesh in a trough under bright
lights, where algae is
encouraged to grow. The growth of the algae
removes some pollutants
from the water. This is a controversial form
of filtration for reefs
and large marine ecosystems invented by Dr.
Adey at the Smithsonian.
Some believe it is a complete filtration
solution, others claim its
use leads to poor water quality and algae
growth in the tank as well.
In freshwater-planted aquariums vigorous
plant growth has been
observed to beneficially consume excess
dissolved nitrates.
CHILLERS
While
not really a filtration, saltwater aquarists occasionally have the need to
lower the temperature of their aquarium water. The high light levels needed in
reef aquaria involve a build up of excess heat. Use of a hood fan and removal
of the ballast from the vicinity of the tank can also help. Submerged pumps are
also a source of unwanted heat, and as a solution, reef aquarists favor the
``non-submerged'' pumps due to the decreased transfer of heat to the water.
A little recognized source of heat control is
through the natural cooling effect of evaporation in wet dry filters, and
through the flow of air over the surface of the aquarium. Nevertheless,
additional
cooling is often required, especially in warm
climates.
This is achieved through the use of
"freon" style cooler units similar to home refrigerators. They either
pass the water through a heat exchange
unit, or pass coolant through a heat exchanger in the tank. Those chillers are
expensive but not many people have had success in the "do it
yourself" construction of chillers. (The "dorm" type of
refrigerator is not powerful enough to be of use, just in case you were
thinking about this.)
Aquarium Maintenance
When set up properly, marine aquariums require minimum
maintenance. The operative word is properly. However, regular preventive checks
of equipment are needed to ensure proper functioning of the entire aquatic
system. Weekly and monthly maintenance tasks are required. In addition, a
series of daily checks should be made. especially during the first few weeks
after the first aquatic animals have been added. Routine daily inspection of
the aquarium system ensures that problems can be found quickly and corrected
before they place the fish and invertebrates in jeopardy.
As a safety procedure, whenever working with aquarium equipment
make sure that the apparatus is disconnected from electric outlets. Always plus
appliances into a Ground Fault Interrupt Circuit and make sure to use drip
loops in all cords. Saltwater is highly conductive and can transmit dangerous
electric shocks. This is especially true when working on lighting elements or
adding water to the aquarium .
It is also important to make sure that your hands are free of
detergents or any other substance that
could be toxic to the fish and invertebrates. If you need to remove an item
from the aquarium, first wash your hands and arms well with plain warm water.
Any products you use to clean the aquarium must also be free of detergent
residues or other possibly toxic materials. It is recommended that you purchase
brushes. sponges, buckets, and other items that will be used only in the
maintenance of your aquarium.
Daily Maintenance
Each day a series of checks should be made to ensure that
everything in the aquarium is functioning properly. Besides turning on the
aquarium light and feeding your fish, you should also routinely remove any food
materials or other debris is visible on the substrate. You should also fish and
invertebrates and observe and behavior.
Filters, Heaters, and other
Equipment
The next daily check involves the functioning of the filters,
lighting, heaters, air stones, protein skimmers, and other apparatus. The
undergravel filter should be examined to ensure that the proper amount of air
is flowing to operate the lift tubes. If the airflow appears diminished, it
could be caused by a faulty air pump, clogging of the airline by accumulation
of salts, or clogging of the air diffuser in the undergravel lift tube. Salt
accumulation is not unusual in aquariums that have been in operation for
several months or more. The salt can be removed by passing a fine wire down the
plastic air tube in the filter to break up the salt accumulation. If this is
not effective, it may be necessary to detach the filter tube assembly from the
undergravel filter and soak the parts in warm water to dissolve the salt
deposits.
Other filters, including an outside filter or canister filter,
should be examined to ensure that they are operating properly. [f you notice a
diminished water flow, this indicates that the filter medium has become clogged
with particulate matter and debris and requires servicing. Diminished flow
could also be caused by a crimp in the hoses of the filter.
The light bulbs should be inspected for any signs of malfunction
and replaced if necessary.
The aquarium heater should then be checked to make sure it is
operating properly and the aquarium water temperature is within the acceptable
range. A properly functioning heater keeps water temperature within the set
range. A slight fluctuation is acceptable and will not harm the inhabit-ants.
If the aquarium water is cooler than desired, adjust the heater control knob or
dial accordingly. Do this gradually, following the instructions provided by the
manufacturer of the heater. A safe approach is to turn the heater dial until
the thermostat light just comes on. Then wait several hours, check the
temperature and read just as required.
If
your aquarium is equipped with a protein skimmer, check to see if it is
operating properly. If necessary,
adjust the airflow to the skimmer, empty the organic and waste that has
accumulated in the collecting cup.
Finally,
check to make sure that the air stones are operating properly. As with
undergravel filters, air stones can become clogged over time as they accumulate
dirt and salt. If a decreased airflow is noticed it may be necessary to remove
the air stone and to clean it well in fresh water. A decrease in airflow can be
caused by crimped airline tubing, improperly adjusted air valves, faulty air
pump, or salt accumulation.
The
condition and quality of the water should also be examined daily. In a properly
maintained aquarium, the water should be
crystal clear and should smell fresh. Questionable odors could indicate the
need for a water change. Water deterioration could be due to improper
filtration, decaying food, or a dead fish or invertebrate.
Fish and Invertebrates
Daily
inspection of the fish and invertebrates in your aquarium ensures that they are
accounted for and in good health. This is best done during feeding when the
majority of the fish swim in the open. If a certain fish is not readily seen,
do not assume that it has died. Since the behaviors of fish differ, some may readily come into the
open.
For
example, squirrelfish tend to hide during the day and feed during the night,
while many species of wrasses hide in the sand for long periods of time.
However most healthy fishes, including squirrels, soon adapt to the feeding
schedule, whatever it may If a particular fish is not seen for several days,
examine the aquarium closely, as it may have died. It is also possible that it
jumped out of the tank if there was an opening in the aquarium cover . This is
not uncommon, especially with certain species like jawfish. First, look on the
floor around the aquarium. If the fish is not found. it will be necessary to
•'" move the rocks a decorations in the aquarium to locate the fish. This
should be done carefully and with as little disturbance as possible to the other
fish and invertebrates.
In
addition to checking for the presence of aquarium inhabitants, their general
condition should be noted each day. The
fish should be examined to see if they are behaving normally. Abnormal signs such as increase in
respiration, scratching along aquarium surface, or frayed fins can indicate
deterioration of water quality, aggression by other tank mates, or the onset of
disease.
All
living corals should be examined. If any invertebrates have died, remove them
promptly and follow up with an ammonia test. An ammonia test is especially
important if the aquarium water is cloudy or has a peculiar odor.
Water Testing
Besides
a general observation of water clarity, water tests including pH, ammonia.
salinity, or any other tests should be performed as required for routine weekly
maintenance. Water tests need not be performed daily except during the initial
establishment of the biological filter or when new fish are added to the
aquarium.
Weekly and Monthly Maintenance
Water Changes
Regular
water changes are fundamentally important in any aquarium. Even though aquarium
water is filtered to remove toxic components, various organic and inorganic
compounds accumulate in the water over time. In fact, if an aquarium is left
without any water changes, radical alterations in the chemical composition will
adversely effect the aquarium inhabitants. These alterations include an
increase in nitrate, decrease in pH, decrease in the buffering capacity,
increase in the concentration of phosphate, increase in organic compounds, and
reduction in various trace elements required by marine organisms, especially
invertebrates.
Ok,
so you have a new (or old) fish tank.
You know you need to clean it, but how.
Do you tear down the whole tank and start from scratch? No way!
Not only is it too much work, but its too much stress for the fish and
bad for the overall system. So what
should you do? Partial water changes.
The
partial water change is just that, a partial removal of a volume of water from
the tank and replacing the water with fresh water. This is beneficial because it will replenish
many minerals and vitamins that become soluble in water. Remove many dissolved organics from
decorations like driftwood, and it removes accumulated nitrogenous wastes like
nitrate. It is also beneficial in aiding
the buffer of the tank pH.
How
much water makes a partial water change?
A few different schools of though come into play here. Both systems work. Choose the one that will be most likely for
you to adhere to. I like to do smaller,
weekly water changes. In small tanks
(less than 55 gallons) I do a 5 to 7% water change each week. In bucket speak, this roughly equals 2 to 4
buckets of water. In a larger tank, I do
10% weekly. A more relaxed method is to
do 20 to 25% monthly water changes. This
had the added advantage of not taking an hour of your free time every week. Both of these will do the job. Of course, smaller frequent water changes are
more gradual and will keep all dissolved organic levels lower, but the key is
to actually do the work. So pick the
plan that you can live with. Certain
fish will dictate their own water change plan.
Some fish, like Discus like more frequent water changes, and some marine
tanks, reef systems in particular may require more frequent water changes.
When
doing your weekly or monthly water changes, it is important to also do some
tank maintenance. Use a gravel vacuum
and stir up that gravel. This is the
most important part of doing water changes.
By siphoning the gravel, you remove all the accumulated detritus from
the gravel. All the fish wastes, and
uneaten food that has accumulated there over the past days. If you have an undergravel filter, this also
helps stir up the filter bed and eliminate any dead spots that may form. A dead spot is any region where the water flow becomes blocked or
stagnant. You may notice a rotten egg
smell when doing your water changes if you stir up any dead spots.
Along
with vacuuming the gravel, you need to treat the water. If you have municipal, or city water they
often treat it with chlorine or chloramine to help keep it clean. Both chlorine, the same stuff you use in
pools, and chloramine is chlorine with ammonia added. Both are highly toxic to fish, and need to be
removed. There are literally dozens of
products out there for this purpose.
Some remove chlorine only, other both.
Some add ‘slime’ to the fish, others add electrolytes, etc. Make sure you use one that I suited for your
water conditions. And if you have a
well, you do not have to de chlorinate the water. Mother Earth does not yet self
chlorinate. But you will have to check
for hardness and pH. Many times well
water is very hard. Meaning it has a
lot of dissolved minerals like calcium and magnesium in it. This is fine for some fish, but not so for
others. So you should treat the water to
adjust hardness and pH to a level that resembles your tank.
And
while you are adjusting and treating your water, adjust that temperature. No one likes to have their hot shower
interrupted by blast of cold water.
Well, no fish like to have a sudden drop (or increase) of 10 degrees in
the tank! This kind of stress is easily
avoidable and will save you countless hours of grief. Temperature shock is a leading cause of
parasitic infection.
Increase in Nitrate:
We
previously noted that once an aquarium biological filter is functioning there
will be a continuous accumulation of nitrate. Even though it has generally been
accepted that nitrate is not toxic, recent research suggests that high nitrate
levels can interfere with the normal growth of marine fishes and have an effect
on the longevity of invertebrates.
Decrease in pH:
Although
several factors affect the decline of pH in aquarium water, chemical
by-products of nitrification are particularly noteworthy. As previously
mentioned (see page 85), the nitrification process results in an accumulation
of nitrite and nitrate. However, these compounds are initially added in the
form of nitrous acid and nitric acid, which eventually become nitrites and
nitrates through neutralization by natural buffers. As the buffer capacity of
the water is reduced, an accumulation of acids lowers the pH.
Decrease in Buffering Capacity:
Natural
seawater has compounds that buffer the water and maintain n the appropriate ate
alkalinity. Over time, the buffering capacity of the water lessens. The
buffering compounds in the substrate eventually also become exhausted. Since
synthetic sea salts contain buffers, the regular replacement of water restores
any diminished buffer capacity.
Increase in Phosphate:
The buildup of phosphate in aquarium water
also upsets the chemical balance. Phosphates originate from the breakdown of
various organic materials and accumulate regularly. Although phosphate is not
toxic at concentrations normally found in aquariums, high concentrations will
coat substrate particles and prevent the release of buffering chemicals.
Partial water changes greatly aid in reducing phosphate.
Increase in Organics
An
increase in organics is another problem in marine aquariums. As discussed in
The Aquarium Conditioning Period various filter media as well as protein
skimmers will remove organics. Partial water changes also reduce the
concentration of organics and the accompanying yellow color of the water. High
concentrations are known to inhibit the normal growth of fish and
invertebrates.
Reduction in Trace Elements:
Trace
elements are found in all synthetic sea salts and in natural seawater. Many
trace elements are required by various marine animals for specific biological
functions. For example, iodine is found in very small concentrations in
seawater, but it is necessary to prevent goiter in fish. Various invertebrates
accumulate large concentrations of certain trace elements, although their
function is not clearly understood. The growth of macroalgae can also rapidly
deplete certain trace elements. Regular water changes help restore the trace
element balance in aquariums.
As
can be seen, regular partial water replacement therefore provides the numerous
benefits of restoring and maintaining proper water quality.
Partial
water changes of 25% or more should be accomplished monthly, or better yet, a 5
to 10% weekly water change should be done. The recommended procedure is first
to mix sea salt with the appropriate amount of replacement water the night
before the water change and adjust the salinity to that of the aquarium. The
next day, using a siphon, remove an equivalent amount of water from the
aquarium and replace with the newly mixed seawater.
Replacing Evaporated Water
It
is important to replace evaporated water weekly to maintain the proper salinity
and chemical balance. Tap water can be used, but in with extremely hard water,
the continual addition of tap water can eventually cause a chemical imbalance.
Under such circumstances distill water should be used alternately with tap
water to minimize the possibility of chemical alteration of the aquarium water.
It must be remembered that to destroy any chlorine or chloramines. municipal
water needs to be treated with a water conditioners prior to addition to the
aquarium.
Cleaning Aquarium Surfaces and
Equipment
At
least once weekly, all aquarium equipment should be wiped with a clean cloth.
This should be done especially on areas where salt has accumulated, including
the aquarium cover, hood, top, and sides of the aquarium. With removable
aquarium covers, the easiest way to clean off collected I salt and dust is to
remove the cover and scrub it under warm running water.
The
outside and inside glass should also be I cleaned. The outside of the aquarium
can be wiped with a cloth and a little glass cleaner. Be careful to use only a
small amount of the cleaner • and never use it on the top of the tank where it
could get into the water.
The
inside glass can be cleaned using various manufactured devices for removing a
buildup of algae. One popular device is the cleaning magnet.
Two
magnets are equipped with special non-abrasive cleaning surfaces. One magnet is
placed inside the aquarium and another
on the outside.
The
magnetic force holds them in place. You simply move the outside magnet that
moves the inside, magnet to remove attached algae. If the inside magnet
accidentally detaches during cleaning, remove the inside magnet, rinse the
cleaning surface I and inspect for any small stones. If this is not done,
remaining sand or gravel will scratch the inside surface of the aquarium. This
is especially important when cleaning acrylic tank surfaces, which damage
easily.
Aquarium
glass can also be cleaned with algae scrapers or cleaning sponges. This device
uses razorblades attached to a long handle. The movement of the cleaning head
scrapes algae off the glass. The sponge type has a sponge attached to a long
handle that will also remove algae from the glass. As with the cleaning
magnets, you will avoid damage to the aquarium by frequently inspecting the
cleaning head of either device to make sure small particles or stones are not
trapped.
Replacing Fluorescent Bulbs
The
fluorescent bulbs used in the aquarium hood have a finite life and must be
replaced periodically. The bulb may still be functioning, but the intensity of
the light will gradually diminish.
Check
with the manufacturer to find out how often to replace the bulbs. For example
if a bulb is rated for a 5,000-hour life and your aquarium is illuminated for
10 hours daily, you will need to replace the bulbs approximately every 7
months.
Cleaning Decorative Aquarium Items
Generally,
there is little or no need to clean the various decorative items used in the
marine aquarium. Algae will grow on various rocks, coral, and shells, in time
giving the aquarium a more natural appearance. In addition, small invertebrates
will colonizing these areas. From time to time, however. you may wish to clean
off excessive growths of algae or accumulated dirt and sediment from coral and
shells. These items can be removed, cleaned, and rinsed with a small clean
toothbrush in fresh water. Never use any type of cleaning solvent or detergent
to clean decorative items. These
products are toxic to fish and invertebrates. Decorative items generally need
to be cleaned only once every 3 to 4 months or more.
Cleaning Aquarium Filters
The
various types of filters used in marine aquariums require maintenance to ensure
performance. Depending on the filter type, maintenance needs to be done
anywhere from every 3 to 12 weeks. You should follow the manufacturer's
instructions for cleaning of filters and
replacement of media.
Undergravel
Filters: Since these filters utilize the aquarium gravel as their filter
medium, the layers of the filter bed can become laden with debris. If the
filter bed becomes clogged, the filter will not function properly. Therefore.
it is important to gradually stir up the top layer of the filter bed once every
few weeks to dislodge particles and ensure a uniform flow of water through the
filter bed. The debris that is stirred up will be removed by an outside filter
bed.
If
the undergravel filter bed is heavily laden with organic materials, use a
special siphon cleaner that removes water as it cleans the lop surface of the
filter bed. This process can be followed once every 4 to 6 weeks or as
required. The frequency is lessened when the aquarium is equipped with an
additional outside filter.
Outside
Filters, including canister filters, re-quire cleaning every 4 to 8
"weeks. depending on the biological load in your aquarium. This entails
removal and replacement of the' activated carbon and filter floss. Always
retain a portion of the old floss and add to the new floss. This ensures that
some of the filter bacteria are retained in the filter.
When
replacing activated carbon, rinse it with tap water to remove fine dust
particles prior to placement in the filter.
Water
Testing should be performed a series of water tests shows that the water weekly
or monthly. This assumes ranges for each quality remains within"
acceptable parameter. pH test is mandatory for all marine aquariums. A pH test
will determine if the pH range is within 7.8 to 8.3. For the majority of marine
aquariums, especially those with invertebrates, the pH should be maintained
within 8.0 to 8.3. As discussed previously, the pH will decrease over time and
hence must be monitored. If the pH has decreased, it will be necessary to make
an immediate partial water change.
A
salinity test should also be made weekly to ensure that salinity is within an
acceptable range. If the salinity has increased, simply add enough fresh
dechlorinated water to bring the salinity back to an acceptable level. As
previously discussed, the salinity is determined by first testing the specific
gravity using a hydrometer.
A
nitrate test should also be made weekly. The accumulation nitrate is determined
by many factors, including the initial number of fish and invertebrates in the
aquarium, amount of food fed, type of filtration system, and extent of algae in
the aquarium since algae utilize nitrogen compounds. aquariums with an abundant
growth of algae will not accumulate
nitrate as rapidly as those with little or no algae. Excessive concentrations
of nitrate in the "water.
While not directly toxic, can
interfere with the normal growth and longevity of marine fish and
invertebrates- Invertebrates generally do not tolerate excessive concentrations
of nitrate in the water.
Other
tests, including those for carbon dioxide
and dissolved oxygen, are seldom required. Once the aquarium is
functioning properly and has completed the conditioning period. The only exception
that would necessitate more frequent testing would be if a substantial
modification is made to the aquarium system, such as the addition of a new filter, a complete
cleaning of the systems, change in the type and amount of food fed, or the
addition of several new fish.
General Fish Background Information
What
is a fish?
A
fish is a vertebrate, meaning it has a backbone. It is also entirely aquatic with a few
noteworthy exceptions. These fascinating
creatures can live in freshwater, saltwater or brackish water.
Basic Anatomy and Physiology
With
ornamental fish we are concerned with four basic groups of fishes.
•
Coldwater (ambient temperature fishes) freshwater
•
Coldwater (ambient temperature fishes) marine
•
Tropical (21-29 ˚C) freshwater
•
Tropical (21-29 ˚C) marine
The
saltwater fish presents a challenge with their tremendous diversity of
shapes. They all generally have similar
organ systems. Freshwater fish present
more uniformity in anatomy. In all fish,
the bulk of the body consists of muscles for swimming. The coloemic cavity for
fish is relatively small.
Integument
As
with mammals, the integument provides the first line of defense against
desiccation, disease causing agents, and some injury. Most people recognize fish as a scaled animal,
however some fish have scale modifications or no scales at all. The scales (if present) sit in ‘scale
pockets’ of the dermis and have a layer of epithelium covering them. Fish are
capable of regenerating lost scales. Rough handling by netting can result in
injury, which may result in bacterial or fungal infection. There are also many external parasites that
may afflict your fish. The gill cover (Opercula) also exhibits variations of
particular note. In some saltwater fish, the opercula resembles more of a pore
or tube, not the typical flap. This is
important when trying to identify fishes.
Gills
These
serve a three-fold function of respiration, excretion and osmoregulation.
Oxygen and other gases are adsorbed by the gills and carbon dioxide is excreted. Oxygen diffuses much slower through the water
than in air. Therefore, oxygen is far
less available to aquatic organisms than in air-breathers. An increase in salinity and/or temperature
will reduce the oxygen content of water.
The general gill structure provides a large surface area for gas
exchange and a counter-current exchange that results in the availability of
approximately 80% of the dissolved oxygen.
Ventilation in most fish results in a continuous flow of water across
the gills. In the first part of the
‘double pump’ respiration, the mouth is open and the opercula are closed which
draws water into the oro-pharyngeal cavity.
The second phase occurs with the mouth closed and the opercula open to
force water out.
Nitrogenous
wastes excretion is the primarily the function of the gills, not the
kidneys. Up to 75% of ammonia wastes
(main excretory product in fishes) are removed by the gills. Chloride cells in
the gills are responsible for osmoregulation and mineral balance. The gills can be damaged by excessive pH,
high ammonia levels in the water and many types of parasites. The response of gills to damage is by
excessive production of mucous that inhibits gas exchange.
Swim Bladder
This
is the glistening white sac in the retropertoneal dorsal body cavity. The swim bladder is used as an
equilibrium-ballast device. In some fish
there may be connections with the inner ear or distal esophagus. Some bottom dwelling fish do not have swim
bladders.
Gonads
Gonads
will vary in size with the breeding condition of the fish. The testes are generally white and smooth
close to the distal portion of the large intestine. In the gravid female, the eggs will fill a
major portion of the coelomic cavity.
Gastrointestinal Tract
The
GI tract is similar to mammals with the length depending on diet type
(herbivores, carnivores, or omnivores).
Herbivorous fish tend to have longer guts than carnivores. In some species there are extensions there
are extensions of the pyloric portion of the stomach called the pyloric caecae.
Liver and Gallbladder
The
liver is yellow-brown to dark red in coloration and is multi lobed. It functions as a mammalian liver does. It will be involved in most systemic
cleansing processes. The gallbladder is
a sac like structure embedded in the liver tissue. It may be small or large
depending on the species and whether the fish has recently eaten.
Spleen
The
spleen is usually bright red in color, species dependent on shape and usually
located near the fundic portion of the stomach. It is the site of red blood
cell production and storage.
Heart
In fish, the
heart is two chambered, although there are four divisions. The sinus venosus, atrium, ventricle, and
bulbous arteriosus. It is located
cranial to the liver and adjacent to the gill (in the ‘throat’ of the fish).
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