Hi, we have had our first hot tub, a Bullfrog A7 with saltwater system, for 1 year now and getting ready for first drain/refill. I got some Ahh some purge to use also, which I learned about after we filled it year ago. I have a digital PH meter and I am thinking of lowering PH to about 6.0 for 48 hours and would like opinions on doing that. I can't find post now but had read some people lowered PH to dissolve any calcium build up in plumbing. I have really had no issues with water the last year but did have some white build up occasionally along water line that rubbed right off. This was mostly until I learned how to keep PH under control. My calcium level was initially at 300, but I plan to lower that on refill using some more soft water. Anyway just wanted to get thoughts on the procedure of lowering PH when draining as a preventive measure for any buildup that might have occurred. If so, is lowering to 6.0 for 48 hours sound good? Thanks