I've read that ammonia is more dangerous--ie, toxic at lower ppm--in hard water with a high pH. And ammonia is more toxic at higher temperatures.

One chart I saw said that, when cycling, the "safe" level for my water at 75 degrees is below 0.4ppm instead of the usual 1ppm that would trigger a water change.

Does the toxicity of nitrite also vary with pH and/or the temperature?

How about nitrates?

from what I understand and someone correct me if Im wrong, but Nitrites and Nitrates arent effected with the Temps at all, with the PH...

nitrAte does have some effect with temperature difference but the impact not toxic.. it is more on mental, stress level will be affected with high temperature and high nitrate..

3 different tank, (A) High temp, High nitrAte (B) High Temp, low nitrAte © low temp, hi nitrAte (assuming high temp = 32 degree celcius and high nitrAte is 150)

in A, fish loses appetite and look stressed and unhappy and hiding in one corner.. in B, fish may be swimming, but fin may be down, slow and tired.. in C, fish behave normal, but maybe only appetite is affected and not eating as much..

comments? as this is is extracted from any source but through combination of information about temperature n nitrAte