Water Quality
Water Quality - Ph - Ammonia - Nitrites - Nitrates
- Oxygen Levels
Filter Filter Filter: Filtration
is one of the most important aspects of keeping your koi healthy. You can
never have to much filtration. Calculate the volume of your pond and make
sure that your pump can handle at the minimum, of turning over the complete
volume of your pond every 2 hours, 1 hour is even better. If you need multiple
systems then the investment is well worth it. Remember that they are living
in there own toilet bowl and us humans need to regulate that water so that
it is as free of waste and detrius as possible at all times.
Water Quality : When
you appreciate that water is to koi fish like air is to humans, you begin
to appreciate why water quality is so important to koi. To illustrate:
imagine you had a very slight gas leak in your house. You can't see the
gas and you don't
recognize the smell, but you find that after a few weeks you don't
feel well. The gas itself is not bad enough to kill you, but your resistance
is lowered, because your body has to constantly work to repair the damage
the gas is causing. In time you find that
you get sick easily, whether it is a cold, the flu or whatever you
are exposed to. On the other hand, if the gas leak suddenly got bad enough,
it alone could kill you. It is very similar with fish and pond water. Poor
water quality will kill your fish faster than
anything else. Low oxygen in a pond can kill every fish in the pond
overnight. High ammonia levels can kill fish within several days. But,
even marginal levels of oxygen, ammonia and nitrates can set your fish
up to fall victim to other life threatening
problems. So, the goal should always be to have the best water quality
possible. There are basically five water quality items you need to be concerned
with, ph, ammonia, nitrite, nitrate and oxygen.
Ph is a measurement
of whether the water is acidic of alkaline. Ph is measured on a scale ranging
from 1 to 14 with 7.0 being neutral. Any measurement below 7.0 is considered
acidic and any measurement above 7.0 is alkaline. The ideal ph for koi
fish is 7.4 but koi will do quite well in water ranging from 7.0 to 9.0
as long as it does not fluctuate too much. Imagine you have a concrete
pond that normally has a ph of 8.5 and you are constantly adding acid to
the pond to lower the ph to 7.4. If each week the Ph bounces back up toward
8.5 again, you are doing much more harm toyour koi than any possible good
that might be gained by getting the ph to stay at 7.4. Koi fish do not
do well with constant change so leave it alone. What you do need to watch
for is a "ph crash". A "ph crash" is when in a relatively short period
of time the ph begins to drop and it won't stop until it reaches 5.5. This
can happen literally "overnight" in a small pond. At a ph of 5.5, koi will
begin to die within a few days. If this happens you can easily raise the
ph by simply adding baking soda to the water. Try adding one cup for every
1000 gallons and check it every two hours until the ph is back to at least
7.0. Anytime all the fish in the pond suddenly begin to act differently
at the same time you should suspect a ph crash. You can lower the ph in
a pond by adding acid. Muriatic acid (pool acid) can be used, but use it
very sparingly because a little goes a long way when used to lower the
ph.
Ammonia is produced
naturally by the koi in the form of waste. 70% is from their gills and
the other 30% is produced through their kidneys. You can't see ammonia
in a pond, but if this ammonia is not removed from the pond the koi will
literally die in
their own waste. The most effective way to remove ammonia from the
pond is with a "biological filter." In a good biological filter, the bacteria
that is formed will remove the ammonia by turning it into nitrites. When
installing a new filter it will take
approximately 2 weeks, after fish are added to the pond, for enough
of this beneficial bacteria to develop to keep the ammonia levels down.
If when you test the water, you find the ammonia level to be high, the
easiest way to lower it is by performing a
30% water change every other day until it reaches a safe level. Whenever
you do a water change, make sure to add some dechlorinator before refilling
the pond to remove any chlorine in the new water. Also, stop or at least
severely reduce feeding
the koi until the ammonia level is under control because the more food
you give them the more ammonia they will produce. Also, raising the salt
level in the pond to .1% when the ammonia levels are high, will help reduce
the toxicity of the ammonia to
the koi.
Nitrites are
produced by the bacteria in your biological filter as it removes the ammonia.
Like ammonia, nitrites are also toxic to your koi. The best way to remove
nitrites from your pond is also with a good biological filter. After the
ammonia bacteria
build up in the filter another bacteria begins to form that will change
the nitrites into nitrates which are relatively harmless. This bacteria
is more fragile than the ammonia bacteria and takes longer to get established.
When installing a new filter, it will usually
take up to 6 weeks after the fish are added to the pond for the beneficial
bacteria, which controls nitrites, to develop to the point where it will
keep the nitrite levels under control. Again, the easiest way to lower
the nitrite levels during this start up period is to perform a series of
30% water change when needed.
Nitrates are
the last chemical produced during the nitrification cycle that takes place
in the biological filter. Nitrates are not nearly as toxic as ammonia and
nitrites are. Nitrates serve as food for plants and algae in the pond.
Usually if a healthy layer of
algae is allowed to form on the inside walls of the pond, it will be
sufficient to keep the nitrate levels under control.
Oxygen levels
in a pond are very important to the overall health of the koi. It is important
to realize that plants and algae produce oxygen during the day light hours,
however, at night the whole process is reversed and plants and algae actually
consume oxygen. This is important because sometimes people will turn
off their pumps at night to conserve energy and wake up to a pond full
of dead fish in the morning and have no idea what happened. We saw one
case where a man had turned off his
pump at night for two years and never had a problem and then during
one hot summer night he lost them all without any warning. The problem
was that the koi had continued to grow until they reached the critical
point to where the oxygen in the pond, during the night, could no longer
sustain them. The most common way to add oxygen to the pond is by use of
a water fall. Anything that disrupts the pond surface will help add oxygen.
The only place where oxygen can effectively be transferred into the pond
water is at the pond surface where the atmospheric pressure on the water
and the oxygen is equal. Placing an air stone in the bottom of a pond will
not add any oxygen into the pond until the bubbles reach the surface and
break. The major advantage of using an air stone at the bottom of the pond
is that as the bubbles float to the surface they bring along with them
the water from the bottom of the pond which is usually low in oxygen. This
creates a constant current of water moving from the bottom of the pond,
where the oxygen level is low, to the surface where it can pick up oxygen.
The down side of air stones is
that often times they end up causing the pond to look like a Jacuzzi,
making it harder to see the koi because of all the bubbles on the pond
surface. An alternative to air stones, that works well, is to use jets
to move the water to the surface where it can be
oxygenated. The advantage of using jets to move the water, instead
of air, is they cause much less disruption on the pond surface.
The only way to accurately test the oxygen level in water is to use
a digital oxygen meter. Oxygen testers start at around $175.00, so for
most people it is not practical to purchase one. Therefore, most people
will have to guess as to how much
oxygen their pond contains. As a rule, if the pond has an average sized
waterfall and you can hear the water flowing you most likely have enough
oxygen. On the other hand, if the koi spend most of the day near the water
fall or are constantly near the surface of the pond you may need to increase
the oxygen level. A pond with a consistently low level of oxygen can contribute
greatly to koi fish that don't grow or that are often times sick.
