The present invention relates to compositions and their use for the treatmentof water. In one embodiment, the invention provides for a compositions andtheir use for the treatment of micoorganisms. This invention also providescompositions and their use to provide clean water in an environmentally-friendly manner. In another embodiment, the invention provides forcompositions and their use in combination with common equipment forcontrolling the growth of micro-organisms, such as with an ozonator or UV-Clamp, in a water system such as in hot tub or pool. Additionally, thespecification describes methods and compositions for controlling the growth ofmicroorganisms in an aqueous system. Using the methods and compositions, onetreats an aqueous system with an amount effective to control the growth of atleast one microorganism. Accordingly, several advantages of the invention areproviding improved water treatment, providing environmentally-friendlytreatment, providing a more user-friendly treatment, and providing water thatis better for human health.