Water chemistry (Nitrate)

Nitrate
High nitrate levels can kill fish. It seems that saltwater aquarists pay more attention to nitrate than do freshwater guys like me. But high nitrate levels in an aquarium can create an "unhealthiness" that is otherwise hard to diagnose. We won't keep nitrates out of our aquariums completely. Nor should we even try. Nitrates commonly result from the decomposition of ammonia, not only a disinfectant but also a natural component of waste products. And nitrate is an important nutrient. The problem is that nitrate becomes toxic at high concentrations. Thus, our task is to keep the nitrate level low. Four simple strategies help us accomplish this task. 1. Don't overstock the tank.2. Don't overfeed.3. Keep the tank clean: vacuum the bottom; remove dead plants, fish, and snails.4. Perform regular partial water changes. Careful aquarium maintenance should keep excessive nitrate levels from being a problem for you. For added peace of mind, however, you can purchase nitrate testing kits at many pet stores.

(please don't mix up Nitrate and Nitrite)