Make tap water safe for fish and promote growth of beneficial filter bacteria with Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner. Tap water contains chlorine, chloramines and heavy metals that are harmful to fish. Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner neutralizes these pollutants, making tap water safe. It also contains seaweed extracts to strengthen bacterial beds and provides a slime coating to help heal wounds and protect fish from abrasions.