I'm hoping I can get some guidance on shortening the amount of time it's taking me to get my basic TA and PH balance when doing a fresh fill on my hot tub. I've been using the 3 step bromine method and try to follow the steps in Waterbear's and Nitro's sticky posts. I generally end up getting things balanced, but it is taking 4 - 5 days to get CH, TA, and PH in the zones - before I can sanitize.. and I assume that's not a good thing.
I have a 225 gal. rated tub, so I assume about 200 gal. capacity. I fill from a municipal water source run through a household filter. My source water has been pretty consistent over several fills, usually:
TA: 30-40
CH: 20 - 30
PH: 7.4 - 7.7
My usual procedure has been to adjust TA with baking soda and CH with pool calcium. Of course, this results in PH going very high. Using the Taylor kit for acid demand, I add acid (mercuric) at the recommended amount. And this is where I find the adjustments start taking a lot of time. When I test again a few hours later, there is almost no reduction in PH. Redo the acid demand, add the recommended amount... repeat....repeat. Even when I have 1 drop on the acid demand test move me from above 8 to 7.2 in the test - adding the recommended amount of acid shows minimal or no discernible difference.
Eventually I get there, although usually with the TA lower than I would like in the 70 range. Up until this last fill I would add in Borax at this point. When I've used it, it really held the PH dead steady. But, since adding it pushes the PH back up and requires the same repeated acid adjustment problem as above, I skipped it last time. But, I had to make a lot more weekly PH adjustments as a result.
Any suggestions on where I might be missing something - or different products to use - or revision of my order would be greatly appreciated. Not only do I have concerns letting the water sit there for several days without being sanitized, but it's really hard to go a week without a soak!!!
I have learned so much from these forums and can't thank you enough for the great effort you put in here!