· Premium Member
How heavily planted is the tank? If you have lots and lots of plants, they will use up the ammonia as it is generated, and none will be left to convert to nitrite, bringing both to zero, where they have to be. Nitrate can be up around 40 or so without harming anything even though that is much higher than desired. How much light do you have and what is the tank size? That determines how much you need to fertiize.