Ammonia

Ammonia is a major waste product of fish and the breakdown of feed and other organics. It can accumulate in aquaculture or aquarium systems, where it will, at the very least, decrease production. It is frequently a stressor that leads to disease, and in other cases it kills fish directly. The only way to detect its presence is to test for it.

Test for ammonia regularly and take corrective measures as soon as you detect it. Severe problems may occur when tests are not performed frequently enough. Once fish have started to die, it is difficult to correct an ammonia problem without losing more fish.

How is Ammonia Formed?
Compounds containing nitrogen are added to aquaculture systems through food (especially high-protein food) and fertilizer.  Much of the introduced nitrogen is broken down by livestock, bacteria and plants to produce ammonia.

Ammonia is found in two forms—one form that is toxic and one form that is significantly less toxic.

• The toxic form is known as un-ionized ammonia (NH₃) and reduces livestock health at levels above 0.02 mg/L.
• The significantly less toxic form is called ammonium (NH₄⁺).  There is almost always some amount of ammonia present, but which form it takes varies greatly depending on the temperature and pH.

At 7 pH or below, nearly all the ammonia (approx. 99%) is in an ionized form. Above 8 pH, the toxic form becomes present at anywhere from 1-10% of the total ammonia concentration.  The actual percentage depends on temperature, with higher temperatures causing an increase in un-ionized ammonia.

While keeping ammonia in a less toxic state prevents deaths, it is best to avoid build-up entirely.  Ammonia removal is done with a strong filtration system, nitrifying bacteria etc.