Purifier PLUS ™ is our premium ion exchange resin mixed with our super effective Carbon-PURE for a media that cleans and purifies aquarium water like no other. It removes dissolved and particulate organics and pollution resulting in pure, polished water that is crystal clear and super healthy. Use 1 cup (250 ml) of Purifier™ PLUS for every 250 gallons of water. Rinsed first in freshwater and then poured into a filter bag. Next place in your sump, filter or other part of the system where there is good water flow. Can also be placed in canister filters, box filters and other common filters. For direction on how to regenerate please visit our website.