Cloverleaf Blanket Answer is a unique blend of minerals and enzymes to combat blanket weed u the nightmare curse of many a pondkeeper. The special formula works in all temperatures and seeks to succeed where many commercial bacteria cultures will fail. It is 100% safe for all pond fish plants and biological filtration systems. UV units or protein skimmers need not be switched off. Unlike some products on the market Blanket Answer is not dependent upon water temperature and is not held back/restricted by high ph levels.