Ammonia Removal by Clinoptilolite in the Transport of Ornamental Freshwater Fishes

Abstract

Abstract The addition of the zeolite mineral clinoptilolite to polyethylene shipping bags containing goldfish (Carassius auratus) substantially reduced the concentration of ammonia in the water during 24 h of simulated transport, in comparison with controls without clinoptilolite. At stocking densities of about 22 or 44 g of fish per liter of water, 10, 20, and 40 g/L of clinoptilolite consistently decreased the concentration of total ammonia-N by about 73, 87, and 93%, respectively. Concentrations of un-ionized ammonia-N never exceeded 0.017 mg/L in bags containing even the lowest weight of clinoptilolite, whereas concentrations as high as 0.074 mg/L were found in control bags without clinoptilolite.