NT Labs Koi Care Chlor-Go is a dechlorinator which rapidly removes chlorine chloramine and heavy metals such as zinc and lead from tap water allowing fresh tap water to be added directly to the pond. Using Koi Care Chlorgo is the ideal water care solution and avoids putting fish in any unnecessary danger from these potentially toxic substances. Chlor-Go is also a great copper remover and has a calming effect on fish being transported. It should always be used in transportation bags and isolation tanks regardless of whether or not tap water has been used.