Because many species of fish are highly sensitive to fluctuations in water temperature, pH, and levels of oxygen and toxic nitrogen, the chemical and biological environment of aquariums must be closely monitored and maintained (Mumpton, 1985). The natural absorption and adsorption capabilities of zeolite make it the perfect candidate to promote the ongoing health and sustainability of aquatic ecosystems. In these environments, zeolite serves three primary functions: to remove toxic levels of nitrogen and ammonium ions from aquarium waters; to provide oxygen-enriched air; to purify tank waters (Mumpton 1985 & 1999).

Ammonium ions produced by decaying excrement and unused food is a leading cause of gill damage, hyperplasia, sterility, stunted grown, and mortality in fish (Mumpton, 1985). Studies have proven that zeolite’s ion exchange properties control nitrogen content and can provide an effective means for

ammonium removal (Mumpton, 1985 & 1999). In fact, studies have found that up to 97 percent of ammonium produced in aquatic systems can be removed by zeolite ion-exchange (Mumpton, 1985). As an added advantage, zeolite treatments are low cost and the mineral itself has a high tolerance to changing temperatures and chemical conditions (Mumpton, 1985).

Hargreaves (1998) reported that formulated feeds, fish excrement, and sediment flux add to nitrogen levels in aquatic environments. When nitrogen levels exceed ponds’ assimilatory capacity, water quality deteriorates because of an accumulation of nitrogenous compounds, like ammonia. Bergero et al. (1994) examined how different kinds of zeolites can be used to improve the quality of tank water. During the study, researchers measured concentrations of ammonia in waters collected from a recirculating system. Findings suggest that clinoptilolite zeolite was effective at ammonia removal due to its ion exchange capacities (Bergero et al., 1994).

Researchers have found that the removal of nitrogen content through adsorption produces oxygen- enriched air that can be used to aerate tanks; fish housed and raised in such environments are livelier and have greater appetites (Mumpton, 1985 & 1999). The quality of water in recirculating systems can be improved by using zeolite supplemented fish feed.