Abstract: A system for dispensing water treatment compositions into a pool, spa, or other body of water is disclosed, which system provides a visible cue that the water treatment is properly dispersing and also provides a visible cue when the desired amount of water treatment has been dispensed. The system comprises a dispenser and the water treatment composition contained within the body of the dispenser, which dispenser and which system provides a readily visual cue that when the water treatment dose has been fully, or in some cases mostly or partially dispersed. For example, the dispenser sinks when fully dosed and resurfaces when empty, and in particular embodiments the water treatment generates visible gas bubbles and/or a color stream as the treatment dissolves.