Home

Ammonia Nitrite & Nitrate Pond Fish

Thu, 06/24/2010 - 22:26 by Splashtastic   Tags:

The level of these three nitrogenous componds in the water is a critcal indicator of water conditions.
Ammonia (NH3) is a highly toxic gas produced by the decomposition of organic wastes and metabolic waste
produced by fish most of which is excreted via the gills. Ammonia is lethal in very low concentrations, depending on species and the levels of other water conditions levels of 0.2 - 0.5 mg per litre will kill fish fairly rapidly. Over longer periods one tenth of this concentration of ammonia can cause an increased susceptiability to disease, and in mind is that even one hundreth of the concentration can cause gill irritation.
Toxic ammonia levels can also be effected by other parameters within water quality such as rising temperatures and PH however an increase in salinity can lower the levels. Ammonia levels must always be checked and regularly, various test kits are available and are very inexpensive when considered against the value your fish are to you.
If you find your ammonia levels are to high it is time to start partial 25% water changes daily until the levels read 0mg per litre.

Nitrites (NO2-) are produced as a breakdown product of ammonia as part of a naturally ocuring sequence of biochemical reactions. This reaction is commonly know as the nitrogen cycle which we will look at under the biological filtration section.

A large diagram of the nitrogen cycle will expand from the thumbnail on the right. Nitrite is highly poisonous, it disrupts the haemoglobin in red blood cells and produces listlessness and oxygen starvation. Raised nitrite levels can prove fatal to smaller koi and sturgeon generally under 8 inches in legnth, however larger koi tend to become more lathargic and may lie on their sides on the pond bottom although they will still swim to the surface to feed. Nitrites generally cause problems within a new pond as the pond has not been of an age to which the natural nitrogen cycle has had time to establish, so it is important to test the levels as with all the elements of water quality by using a test kit.
When testing for nitrites if you find the levels to be at 0.15mg per litre you will need to make partial water changes of 20 - 25% per day to lower the level. Also as with ammonia the salinity of the water can reduce the toxicity levels of nitrites we look at the use of salt in our treatments page.

Nitrate (NO3-) is the third nitrogenous compound in the biochemical sequence, this element is far less harmful to fish and other aquatic life when compared to nitirtes and ammonia. In fact koi can tolerate very high levels to which would have to be of extreme quantities which would be very rare to find in your ponds. Koi fry and fish eggs are more likely to suffer with high levels of nitrate as they are far more sensitive to water conditions.
Nitrate is used as a fertilizer by algea and a good indicator of high levels is when the water suffers an algal bloom ( green water) most commonly seen during mid summer when the water temperature has risen. Various test kits are used to monitor the nitrate levels however unlike ammonia and nitrite the toxicity levels of Nirate would very rarely be seen or to cause harm to your fish.

»
  • Share/Save
  • 1648 reads