What are Nitrates?

Nitrate is a by-product produced by the nitrifying bacteria (Nitrosomonas bacteria) through the consumption of nitrites. The bacteria colony convert the deadly nitrites into the comparatively harmless nitrates; although, high concentrations of nitrates can still adversely affect the fish population. In aquariums where the nitrates are left to accumulate to high levels (100+ ppm), fish immune systems are compromised and the door is opened to diseases. Nitrates accumulate within the aquarium and are removed via regular water changes. No form of filtration (biological or otherwise) will remove nitrates from the aquarium. Plantlife and algae, however, help in controlling the nitrate levels as plants consume nitrates as a source of nutrients.

Tests for nitrates should be done on a weekly basis, or however often you change your water. Nitrate levels aid in determining how often to do water changes, and how much water to change. Ideally, aim for nitrate levels within the 20-50 ppm range. Depending upon your local water supply (some of which contains nitrates), the ideal range may be difficult to attain. Presence of nitrates is a good indicator as it confirms that your nitrifying bacteria colony is alive and well. The first sign of nitrates is indication of a "cycled" tank.

Optimum level of Nitrates: < 50 ppm

Removal: Plants/Algae, Water Changes