Python Multi-Purpose Water Conditioner is a water treatment solution that makes tap water safe for freshwater and marine aquariums by neutralizing chlorine, chloramines and heavy metals. This fast-acting formula contains herbal extracts that relieve stress resulting from handling, transportation, and environmental changes. It also coats fish fins and scales to protect against minor wounds. Use this product when adding new tap water to your tank, setting up new aquariums, completing water changes, handling/transporting fish, or when minor wounds are visible. Multi-Purpose Water Conditioner is Step 1 in the three step Python water treatment system, along with Pythons Multi-Purpose Bio-Clean and Multi-Purpose Bio-Support. Safe for use with aquarium fish, invertebrates, and plants. 16.2 fl oz of Python Multi-Purpose Water Conditioner treats 960 U.S. gal of water.