Tetra Pond Pond Block Algae Control SolutionTetraPond Pond Blocks will help keep algae out of your pond! Pond Blocks are an easy, effective method of ornamental pond algae control. Simply drop into your pond regularly to restrict algae growth and help keep your water clear. Buy in bulk to save even more on your regular algae treatment! Pond Blocks are a convenient way to control algae in ornamental fish ponds Easy solution to keep nuisance algae growth under control Clear cloudy water and