Cleaning a Moldy Hot Tub

I would suggest now that the water is out. Use some comet to scrub the discolor out then use bleach and water solution to rewash it down, rince with lots of water. When you refill the tub add a cup of bleach to the water and the bleach will stop this from coming back. Check to be sure the filter is clean as well. If you think about it swimming pools have bleach in the water but don't add to much bleach, I hope this helps, God bless you

Twice a year I drain and clean my hot tub. To get rid of any mold, etc. I spray a little Clorox II on a rag and wipe. Then I wipe the area with a clean wet rag. If that doesn't work, I use a little soft scrub with bleach. Then throughly wash with water. Be sure not to let any of this stay in your tub.

Look up don Aslett and find Showers n Stuff on his website. It is not cheap but cleans hot tubs, tubs showers etc better than anything. I have used it for years and cleaned bathrooms in my daughter's apartments as she has moved from college, to med school to residency. It makes stuff sparkle that you would not believe it could.