A water treatment device that chemically treats tidal water. The water may, if desired, be salt water or fresh water. The water treatment device is substantially cylindrical with paddles extending outward from central hubs. The paddles are T-shaped and are perforated. The perforation aids in water treatment by aerating the water as the tide movement turns the paddles. The water treatment device has a central perforated tray that is slidably insertable into the central hubs. The central hubs are open in the center to permit the aerated water from the paddles to come in contact with the water treatment chemicals in the central tray. The perforations of the central tray allow the water treatment chemicals to come into contact with the surrounding area to treat the tidal water.