ZeoSand is a refreshing, green-colored zeolite. This high-purity, natural zeolite offers a unique three dimensional honeycomb structure and rough, pitted surface. ZeoSand’s crystal structure, irregular shell, and high surface area make it a highly effective trap for fine particulates and ammonium ions. Natural Zeolites were formed millions of years ago when alkaline salt water altered deposits of volcanic ash. Use ZeoSand for Filtration In: Private and Public Swimming Pools Municipal Drinking Water Municipal and Industrial Waste Water Water Parks Aquariums Aquaculture Zoos NSF/ANSI-50 Approved for use in all Sand Filters. Each bag of ZeoSand is 100% natural zeolite of the highest quality commercially available. In addition to being a superb filter medium, natural zeolites are widely used as soil amendments and animal-feed additives.One 25 lb. bag of ZeoSand replaces one 50 lb. bag of sand, and lasts just as long.