MrBill

Hello Tom, I also have a 24,000 gallon pool, and after changing the water last year with the same tap water, I didn't have any problem with the wild pH swings I get with the spa. BUT - I'll run down to the local pool supply store today and get a TA test kit, then report back here what happens. Thanks, Bill

Periodically I change the water in my spa, using tap water. I then put 2 bromine tablets in the filter and let the pump run for a few hours while it heats (220 VAC) up the water. When I check the pH, it is very high, so I use dry acid (pH down) to bring the pH down to 7.4. The next day I check the pH, and even though nobody has used the spa the pH is very high again. This will keep happening for 10 days or so, then the pH will stabilize. I've thought about adding stabilizer (cynauric acid) to stabilize the pH, but been told that this will work only with chlorine levels. So why does is take so many days to stabilize the pH level? What can I do to have it stabilize right away? Thanks, Bill