Crystal Blue Natural Pond Cleaner - Muck and Sludge Remover, Safe for Koi - 1 Gallon Eliminates muck, dead leaves, odors and other organic matter that can harm a pond or lake Super charges naturally occurring bacteria to consume micronutrients Safe for humans, fish, livestock, pets, birds, swimming, consumption and irrigation 1 gallon treats 1 surface acre, 4-feet to 6-feet deep This product is not meant for algae treatment