Any fish produce waste as we all do and are a potential source of ammonia, as it breaks down and burns it releases energy.
Most of the waste is generally ammonia, a substance that is highly toxic to fish. In large ponds which hold a lot of water ammonia is normally diluted and washed away, the levels can accumulate in smaller ponds with less water, over populated ponds, and an inadequate filtration system.
Some types of bacteria break down ammonia to get energy, they add oxygen and form a substance called nitrate. Also different sorts of bacteria turns this nitrite into nitrate by adding more oxygen. These nitrates can be used for food by plants. †Both types live all over but can be given a home with ideal conditions and a good filter.
We now have what we call a nitrogen circle as nitrogen is the element common to ammonia, nitrite and nitrate, the cycle starts with feeding the fish and their waste feed the plants, isnít nature a wonderful thing sometimes.
If you find levels are increasing this can be down to a number of things such as, over feeding, over population, and the filtration system being too small for the size of the pond or even the filter being partially blocked.
Low temperature, low oxygen or any chemical treatments you may have used can also cause levels to increase.
As a short term solution to try and lower the levels, do a partial (up to 20%) water change daily (remember to try and not use tap water) also increase the aeration and filtration system to maximum.
There are many good test kits on the market and may well be a good investment if levels keep creeping up, you will then be able to pinpoint the problem and rectify it.
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