In order to maintain indigenous fish populations it has become necessary in many countries to introduce stocking programs for coarse fish in addition to the ever increasing activities involving game fish. These demands have placed extreme pressures on hatcheries and farms already operating with limited facilities. The easiest way to increase production without vast capital outlay is to increase the number of fish being reared in a given volume.
It is obvious that when the fish density per cubic meter is raised the risk of infection increases proportionally. In order to maintain the survival rate as high as possible it is of vital importance to ensure that no water borne disease can enter the system - this applies to circulating systems as well as once through arrangements. An ideal method of disinfecting water is by ozonation in a contact tank prior to use. Ozone is a very powerful bactericide and viricide and, unlike other agents, it leaves no undesirable residues.
The latest available advanced ozone technology, which will enhance efficiency and be environmentally beneficial, now lies within the reach of all operators.