A composition for the treatment of a liquid, particularly a body of water, such as a swimming pool, spa, or the like. The composition includes calcium hypochlorite, a water soluble zinc salt for controlling algae, and sodium aluminate as an agglomerating agent that may safely be combined with said calcium hypochlorite and said zinc salt. A floating chemical dispenser for containing and dispensing chemicals to treat a body of water. The dispenser includes an upper end float, a container adapted to contain chemicals, the container removably joined with the upper end float, and a free end float joined with the container. The free end float is configured so that a central axis of the container and upper end float is not substantially orthogonal to a surface of the water.