White water mold in a spa is not common at all. When it does show up, it’s usually in a spa that is being sanitized with one of the biguanide sanitizers (Baquacil, Baqua Spa, etc.).
To test for white water mold put some spa water in a glass jar and add bleach. If the flakes disappear after a while, it was white water mold. White water mold will not harm you but its very unsightly and quite difficult to completely kill off. If you don’t kill off every last bit, it will return.
I can’t guarantee this will completely stop the problem, but the best solution is to thoroughly purge your spa with HTS Total Cleanse. You might do it twice for good measure. Then, using dichlor, raise the chlorine level in your spa to 20 ppm and keep it there for several days. Don’t use your spa! Then drain and refill.
