The majority of my duties resided in the in the isolated laboratory. In the isolated laboratory, there were six 1-meter tanks. The tanks were part of a recirculating system, reusing water for the rearing of aquatic species. The major principle behind the use of recirculating aquaculture systems is the decrease of consumption of water that can be beneficial in areas of little water flow or in areas where water quality of the overall watershed cannot be influenced by effluent of aquaculture systems. Water parameters of particular interest include nitrogenous compounds, dissolved oxygen, settleable solids and less important parameters.
Water quality is of constant evaluation in a recirculating aquaculture system.
If water quality parameters reach a high or a low of a given spectrum, fish kills can occur. Water quality is managed by the components of the recirculating system. The biofilters use Nitrobacter and Nitrosomonas to break down ammonia produced by the fish and convert it to nitrite and then to harmless, water soluble nitrate. The biofilters also account for some retention of settleable solids. Clarifiers are used as a means to settle fecal material, uneaten food, and flocculants.