Abstract: A water treatment device which is attached to the feed hose immediately above or behind deep water pool cleaner. Includes a cylindrical body that is slotted on either side within which a water treatment substance is housed. An outer cylindrical sleeve that rotates over the main cylindrical body is used to regulate the flow of water over the water treatment substance such that quiescent conditions prevail inside the holder. The device is equipped with buoyant end caps as to minimize impedance of pool cleaner to which is it attached. Provides distribution of dissolved water treatment substance throughout the entire body of water from the bottom up.