Water Stats Question

[piranha_tim]

Ok here was my understanding

Ammonia is created from the fish and has toxic affects.
A bacteria converts ammonia into nitrites which prevent the fish from getting oxygen.
A second bacteria converts the nitrites into nitrates (a almost harmless particle which isn't damaging until 1000ppm which is extremely unlikely if doing water changes)

Am I wrong because I see alot of people talking about Nitrate levels needing to be closely monitored.

 

[piranha_tim]

Think I found an answer to my own question ... I will start testing for it.

 

[Colin_T]

Ammonia is produced by anything that breaks down in water, be it fish food, fish waste or rotting plants. Ammonia can be more toxic depending on the PH of the water. In alkaline water (PH above 7.0) ammonia becomes really toxic. In acid water (PH below 7.0) it isn't very toxic.
A few types of bacteria eat the ammonia and convert it into nitrite. Then more bacteria eat the nitrite and convert it into nitrate.
Nitrates are reasonably harmless to many fishes but invertebrates like shrimp and corals don't tolerate levels above 50ppm and most do better when the levels are kept below 20ppm. Fish are more tolerant and healthy fishes can tolerate the nitrate levels going up to 100ppm or more. However, if a fish comes from water with a low nitrate level and is put into a tank with a high nitrate level, then it will suffer a lot of stress and could die. The fish are only tolerant of the high levels if they are in the water while the levels are going up.
I don't know of any test kits that read above 100ppm and I doubt that water would get to 1000ppm without killing the inhabitants.
You should try to keep the nitrates as low as possible due to the fact it doesn't normally occur in the wild. The Amazon and other water ways around the world have de-nitrating bacteria in the rocks and mud which breaks down nitrates and removes them from the water. Plants also use ammonia and prevent nitrates building up as well.
If you have nitrates in the tap water then try to keep the nitrate levels in the tank at the same level as the tap water.