Renee--We also dumped our water early and refilled per instructions from so many of the regulars on here when we first started out and have had no problems since with foam. We cleaned the filters at the same time we dumped. A reminder...if you use lotions, etc., on your hands and then test your water, you maybe creating issues that way even if you are showering before entering the tub for a soak. It is amazing how little of any product can cause mountains of foam in a hot tub!!