Aquaculture

Oxygen and ammonia are the two most important parameters in aquaculture operations. While oxygen can be easily controlled ammonia on the other hand is much more difficult to mitigate and is highly detrimental to the health of fish. The natural generation of toxic levels of ammonia (NH3) and hydrogen sulphide (H2S) by large densities of fish in aquaculture operations affects fish tissue, growth rates, oxygen utilization, disease resistance and causes mass mortality.Zeolite is currently used in commercial fish farms to reduce ammonium (NH4) and hydrogen sulphide levels resulting in increased growth rates and population densities. Zeolite is alsoused for fish transportation allowing the delivery of more fish over a longer period of time. Zeolite has a high selectivity and capacity for ammonium via cation exchange capacity (CEC). Once the ammonium ion is within the zeolite lattice, it is not water-soluble. When used as an ion-exchange filter medium the zeolite can reduce ammonium content of circulating freshwater from aquaculture systems by as much as 97%. Piper and Smith (1982) suggested that a water recycling system with a zeolite filter system can allow up to a 10 fold increase in fish density. Zeolite also reduces ammonium content in discharge waters in order to meet environmental requirements. Zeolite is 100% natural, durable and can also be simply regenerated using a brine solution (with a rinse) for repeat cycles of this ion exchange filter bed. Zeolite can also be broadcast over the surface of a pond to be effective in reducing ammonium. The pond-bed sludge can be recovered and used as a nutrient enriched slow release fertilizer. Refer to the 'Soil Conditioning' menu item in the Agriculture Section.The addition of zeolite to ponds and tanks also controls the growth of algae.

The required zeolite quantity for your operation depends on water pH, temperature, volume along with fish species and population density. When the optimum quantity of zeolite is used, the ammonium level is reduced at a rate highly dependent upon the rate of water movement. A variety of systems have been designed for reduction of ammonia in fish rearing environments.