Fast-acting, liquid algaecide._x000D_ Kills all types of algae, including green and mustard algae._x000D_ Non-foaming formula will not make your pool water cloudy._x000D_ Save enough for swimming directly after treatment._x000D_ Not recommended for use in well water as staining could occur._x000D_ Potent''s algaecide should be diluted and premixed before use._x000D_ Algae : Algae are microscopic single celled forms of plant life that are introduced into the water by wind and rain from the atmosphere. There are 30,000 different varieties of algae all containing chlorophyll. They are one of the hardiest and most widespread living organisms on this planet.There are three main categories :_x000D_ Green Algae : usually floating algae though they sometimes cling to walls This is also the fastest growing algae and accounts for most 24 hr algae blooms Pool water becomes turbid with a green growth that renders the pool uninviting and dangerous to use as it is difficult to see the bottom of the pool. Prior to the green coloration appearing, the sides of the pool have a slippery feel and the water becomes hazy and exhibits a high chlorine demand._x000D_ Mustard (Yellow) Algae : appears as a yellow powdery deposit on the pool, usually on the shady side. Once established, it is chlorine resistant and can exist in the presence of 3-5 ppM free chlorine. This is also a common algae which grows in aquariums in areas that get little light._x000D_ Black (Blue-Green) Algae : evident by the formation of 1 to 3cm sized black (or dark blue green) spots, tenaciously adhering to the pools surfaces. Black algae forms a layered structure where the first layer (which chlorine may kill) protects under layers from further destruction. Black algae is similar to the black algae that is found on bathroom shower tiles and in silicone seams near the bath. It is also found in aquariums as dark blotching on the glass sides This form of algae is very slow growing but very hardy. It is extremely chlorine resistant._x000D_ An algae bloom can turn clear clean water into a green swamp overnight. The pH can climb (as algae consumes carbon dioxide which helps keep pH down), and the pool walls become slippery and hazardous underfoot. Once algae is visible a substantial problem exists. Algae takes in carbon dioxide and gives off oxygen like most other plants. Most bacteria found in swimming pools take in oxygen and give off carbon dioxide. Each consumes the by-products of the other for growth. It is desirable to use a chemical program that assures both bacterial and algae control.