AS far as I know the only oxidizer that is supposed to be used with biguinide (generiic name for Baquacil, SoftSwim, Revacil) is 35% hydrogen peroxide (a very dangerous chemical in this concentration). It is a liquid. I do not believe that MPS (potassium monopersulfate), which is probably what he sold you, is compatable with biguinide but I might be mistaken. Does it say that it is compatable with biguinide on the labeling? If not I would not use it!