Hydrogen form amber colored cation resin dyed purple that changes to yellowcolored as resin exhausts.Aquarium treatment includes conventional deionization and color indicator resins that are selective for specific contaminants such as silica, ammonia, phosphate, nitrate, etc. Suzhou X Chemical offers a large number of ion exchange resins and adsorbent medias suitable for use in the aquarium industry. All XResin’s products are suitable for aquarium use with very low levels of toxic leachables