Hello, I'm a fairly new hot-tub owner, and have found tons of valuable resources on this forum. Now that I have a slightly complicated question, this was quickly my first-choice to seek guidance My tub is 425 gallons (Alps Spas Q-90), last cleaned and refilled on 1/22/17 (sodium bromide + floater + MPS), consistently tested with a Taylor K-2106 kit, and set to 102F.
Problem is my measurements today have me really scratching my head. TA dropped, and my CH plummeted. I've been busy so the tub's only seeing 1 or 2 bather-hours a week lately. Here's the last few measurement entries in my logbook:
2/11/17: pH=7.3, TA=120, CH=100, SI=-0.3, TB=0.5
2/12/17: pH=7.6, TA=130, CH=100, SI=0.1, TB=5
2/16/17: pH=7.6, TA=130, CH=90, SI=0.1, TB=4.5
2/20/17: pH=7.4, TA=90, CH=40, SI=-0.7, TB=5
Should I be worried that CH and TA tanked? I know bromine is acidic, which can lower pH and TA over time, but I've never seen my calcium dive like that.
Also, I did add Leisure Time "pH Balance" during this last refill, which says "Note: due to the unique buffering capacity of Leisure Time pH Balance, it is not necessary to adjust the calcium hardness level in your spa". Was that a mistake? Could it be interfering somehow?
Thanks in advance!