Oxygen is a basic necessity for life. Fish absorb oxygen from the water as it passes through their gills and discharge carbon dioxide back into the water. The carbon dioxide is exchanged for oxygen at the waters surface. This process is magnified if the water is agitated, the most common method of agitation is through the use of air diffusing stones such as those used to operate an undergravel filter, this process is called aeration.

The fish also discharge ammonium, through their excrement. Ammonium, which is relatively harmless is converted into the toxic product known as nitrite by bacteria present in the aquarium substrate, filter and in the water. In a well maintained aquarium such as those serviced by Executive Aquarium, other bacteria present in the tank will transform nitrite into harmless nitrate,which, however, is also toxic at high levels.

Ammonium and other organic toxins will build up from leftover food that is rotting and from decaying organisms (plants, fish, and so on), so it is important to follow the feeding instructions you receive from Executive Aquarium closely as they will be tailored to fit the needs of your specific aquarium.

A regular maintenance program can insure that toxins which are always present in an aquarium don't build up to deadly concentrations, keeping your fish happy and healthy.