Nitrite and Nitrate Fraternal twins

Nitrite and Nitrate Fraternal Twins, both created by living organisms

Buy the book

Ammonia, the first toxin to be converted in the nitrogen cycle is created from waste. When ammonia is present, and the environment right, beneficial bacteria will form to feed on it. These friendly bugs convert the toxin into nitrite, the second toxin to be converted. Nitrite is actually friendly bug pooh. When nitrite is present, another type of friendly bug forms to feed on it, converting it into nitrates; the third and final toxin to be converted in the nitrogen cycle. The second and third toxin are closely related; very different from ammonia


Nitrate poisoning is easily detected because the fish sits on the bottom and often loses its appetite in the early stages


The nitrite and or nitrate levels in your fish’s blood stream will be the same as the levels in their tank or pond water; unless the toxins are safely converted by water treatment specifically designed to convert nitrite. Water treatment doesn’t actually change a toxin, but binds to it, making it insoluble and impossible for the fish to absorb the toxin into the blood stream


Safe nitrate levels in goldfish tanks or ponds


Desired levels of nitrate are 12 ppm maximum for aquarium or pond water, so the fish’s blood will be the same. Natural and healthy bodies of water have a reading of 12 ppm or less, so we should assume these are tolerable levels for our fish. Although these two toxins don’t remain in the blood stream once the toxin levels are lowered in the water, the damage may be long term according to how great of levels and for the length of time the fish is exposed


Nitrite and nitrate fraternal twins


Nitrates are converted to nitrite by enzymes found in the digestive tract, but nitrates absorbed directly into the blood stream from the water remain the same. A fish can have nitrite and nitrate poisoning either or both; a very dangerous combination because these toxins are so closely related; both depriving the blood of oxygen. Nitrates can also convert back to nitrite in your fish tank or pond, but only in trace amounts. This is because the fish are excreting bodily fluids into the water


Nitrate, the Gentle Giant

If your cycled tank or pond shows nitrite readings, you could have a spike in the cycle, or you may need to increase your water changes to improve the overall quality of water; increasing the Redox levels


Nitrite and nitrate fraternal twins


Both toxins reduce the oxygen levels in the blood, but nitrates more so than nitrite. This may be because nitrite typically rises to a specific level before being converted to nitrates, subsiding, and reducing in quantities, where nitrates remain in the water consistently in a cycled tank or pond


Can goldfish tolerate nitrite?


If fish are subjected to nitrite temporarily during the cycle; the harmful effects may be short lived, and the fish could make a complete recovery, but fish exposed to high nitrate levels indefinitely may not be so lucky. One toxin is short lived in the cycle whereas the other is a constant threat


It’s possible that goldfish suffering from nitrite or nitrate poisoning will be more sensitive in the future depending on the severity of the poisoning, but only because it has never fully recovered, or is subjected to the toxins repeatedly as often happens in a novice’s goldfish tank or pond. Unaware of the nitrogen cycle, the goldfish keeper breaks the cycle unknowingly, again and again


Can goldfish tolerate nitrates


Goldfish that have been affected by one or both toxins need water that is free of nitrite; low in nitrates with remaining levels being converted; water that ranges on the high side of the comfort zone for pH, KH and GH, and water that is rich in oxygen


Symptoms of nitrite poisoning are shown in the photo below; red veining throughout the body and most prominent in the tail fin as red streaks. Unfortunately, symptoms are slow to appear and often go unnoticed


Nitrite poisoning


Nitrite and nitrate fraternal twins


The fish in the photo below has been poisoned by nitrates, its body exhibits a slight bend to the side that will increase if the levels continue to rise


nitrite and nitrates fraternal twins

Nitrite and nitrate fraternal twins

If your fish has been poisoned by nitrite, and is gasping, raising oxygen levels by installing a pond pump in the tank or pond water is the key


Refer to:
Oxygenating Water


Nitrite Poisoning




Oop Boost to oxygenate water


Goldfish Care


All rights reserved
Author: Brenda Rand