Algae Eater is not an algaecide or a poison; it is a powerful blend of microbes that removes algae from a variety of hard surfaces. Algae Eater is an all-natural and highly-efficient alternative to standard hazardous chemicals which require hard scrubbing or damaging power-washing. It renews the appearance of algae covered surfaces making them look new, again. Conventional cleaners, like chlorine-based products, require multiple applications and last only a few weeks. In fact, when using chlorine-based peoducts (which are 99% water), they create more algae growth than they remove. Algae Eatertm creates a barrier on the treated surface to protect and prevent algae build-up for at least six months.