Ammonia In Ponds and Aquariums – The Invisible Killer

Ammonia in ponds and aquariums is a common problem. Ammonia stress and poisoning is often the number one cause of fish illness and deaths when setting up new aquariums, small ponds and quarantine tanks. This is often referred to as ‘New Tank Syndrome’. It is not usually as common a problem in new larger ponds because the ammonia is diluted in the larger volume of water and doesn’t reach toxic levels. Ammonia stress can also occur in well established ponds for a variety of different reasons. It also usually the first step in a parasite or bacterial outbreak because it stresses and weakens the fish making them more vulnerable to pathogens in the water.

Luckily, koi and goldfish as well as many aquarium fish are quite resilient and can withstand low ammonia levels for a few days without any adverse effects. But ammonia levels can rise to dangerous levels quite quickly and lead to serious fish health problems and deaths.

What is Ammonia and Where Does it Come From?

Ammonia is the primary waste product of fish. It is excreted mainly through their gills and to a lesser extent as urine. It can also come from decaying plant matter, dead algae or dead fish or other animals in the pond.

What are the Symptoms of Ammonia Stress?

The first signs of ammonia stress are often the behavior of the koi or goldfish. In ponds or aquariums with high ammonia levels, fish will often become less active and hang at the surface of the water gasping near waterfalls or filter returns.

Other signs include: