Abstract: A system, composition and method of treating a body of water with an active in a tablet form or contained in a water soluble container to improve overall water quality and ensure adequate dispersion of the active. The composition preferably comprises active(s) and an effervescent couple in solid form. The method preferably comprises dispensing a treatment composition by dropping or throwing the pellets or water soluble containers into the water. The water soluble containers preferably are bag-within-a-bag containers, with an inner bag and outer bag each having the treatment composition and air. Upon contact with the water, the effervescent couple will react to form carbon dioxide, which aids in dispersing the active and any optional ingredients in the treatment composition throughout the water.