Are your tanks clean? If they have chemical buildup in them, that could cause it. Or it could be from your water source. The water quality at the tap at my house varies depending on the time of year. You might try using distilled water with the photoflo for your final rinse. Or do what I do, and use your fingers to squeegee away the excess water when you hang them to dry. Though, the finger squeegee method seems to make a lot of people angry. I hear claims of scratches and stuff, but I've never experienced any. It probably depends on what condition your skin is in. Either that or technique. All I know is, it works for some, and not for others. And apparently if you're in one camp, then the other camp is your sworn enemy.