Doing a partial refill on our in ground spa revealed a thin white film on all the surfaces below the water line. There are some streaks without film. Feels completely smooth to me. Trying to figure out what it might be. Possibilities I'm considering:
Bromine build up: Sanitizer is bromine and we sometimes struggle to keep the levels down (in line brominator that I think was meant more for a pool than a spa.) Would excess bromine adhere to the walls?
Baking soda Film: Has anyone ever had issues with the baking soda they use creating a white film on the sides of their FG pool or spa? I add baking soda weekly to keep the TA from dropping. It regularly tests at 40-50 and I add enough baking soda push it up 20-30 once a week.
Calcium scale: This is the "go to" option, right? But, I don't see how it could happen with my chemistry. CH is around 200-220 without treatment. LSI calculations run slightly negative. Testing 2x a week. In the last 75 testings, LSI has only been positive 17 times, the highest reading being .33. With those numbers is scale build up still possible?
Thoughts?
Taylor K-1005 test kit. 550 gal, Latham Mystic FG in ground spa in Chrystite Sapphire blue installed in 2020. Brominator tabs. Baking soda used for TA/PH control. Oreda CV-600 enzymes once a week for organics. Partial water refill 2x a year. Temp ranges 80-104 year round. Covered in cold months. Pump run year round in cold months, 4 hrs daily in summer. Jandy Pro Series CS Cartridge Filter. Handy Pro Series Stealth Pump. Hayward brominator. Jandy Pro Series JXi Pool and Spa heater.
Bromine build up: Sanitizer is bromine and we sometimes struggle to keep the levels down (in line brominator that I think was meant more for a pool than a spa.) Would excess bromine adhere to the walls?
Baking soda Film: Has anyone ever had issues with the baking soda they use creating a white film on the sides of their FG pool or spa? I add baking soda weekly to keep the TA from dropping. It regularly tests at 40-50 and I add enough baking soda push it up 20-30 once a week.
Calcium scale: This is the "go to" option, right? But, I don't see how it could happen with my chemistry. CH is around 200-220 without treatment. LSI calculations run slightly negative. Testing 2x a week. In the last 75 testings, LSI has only been positive 17 times, the highest reading being .33. With those numbers is scale build up still possible?
Thoughts?
Taylor K-1005 test kit. 550 gal, Latham Mystic FG in ground spa in Chrystite Sapphire blue installed in 2020. Brominator tabs. Baking soda used for TA/PH control. Oreda CV-600 enzymes once a week for organics. Partial water refill 2x a year. Temp ranges 80-104 year round. Covered in cold months. Pump run year round in cold months, 4 hrs daily in summer. Jandy Pro Series CS Cartridge Filter. Handy Pro Series Stealth Pump. Hayward brominator. Jandy Pro Series JXi Pool and Spa heater.
I doubt the use of baking soda has anything to do with what you are seeing, and your CH level has been fine, so I think it's safe to rule-out scale. I wouldn't think bromine would cause an issue either. More than anything I'm thinking you may just be seeing a change in the gelcoat over time. The 2-3 year mark seems to be fairly common time frame for pool/spa products as they undergo a reaction to chemically treated water.