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Full disclosure...... I'm new to this and won't pretend to know like some others in here do, but here it goes. I have the same concerns. My TA is like 30ppm and my PH is 7.4 so I'm letting it ride because when I tried adding baking soda to bring up the TA it shot my PH up to 8.5. and then when I added muriatic acid to drop the PH it pulled down my TA with it. One thing I noticed that helped my water quality was bringing my CH up from 50 to 150. Water seems softer and easier to maintain. Again this is just my 2 cents, albeit an unexperienced 2 cents.
First, thanks for all the info on this site. I just moved into a new house with a ~500 gal 2005 Cal Spa tub. I was able to drain and refill and have been working on balancing. I'm using bromine for sanitation and the hot tub has an ozone. My hardness is normal if not a bit on the low side, forgot the exact number. I was having issues with high PH ~8-8.1 and Low TA. Like around 30-50 if not lower. My main question is that I seem to see conflicting info on here about how big of an issue low TA is. I was finally able to get PH in perfect range, but my TA is very low like around 30. I added a little TA up from spadepot.com last night after I tested the PH. I haven't got a chance to re-test, but I am concerned that it will creep my PH up again. I'm using a Taylor Bromine K-2106 test kit. My Bromine Level has been good, though it trends a bit on the high side (between 5-10, though it was actually a little low on Sunday, so I increased the dispenser and it's back in the 5-10 range, probably right around 6.5-7). It's been about a month, and I've noticed some pretty decent water loss, we use it ~4 times a week. And I'm in South Dakota so it''s usually cold. So I imagine that's the reason for the water loss. I need to top it off tonight, so this A.M. I opened up the bromine dispenser up again to about 5.5. So I guess my two questions are: 1. Is low TA okay, if I keep PH in proper range? If yes, how low is too low? 2. What do I need to consider/anticipate when topping off, I opened up the bromine because I figure when I top it off it will dilute the sanitizer, maybe this thinking is totally off. What will be the top off impact on my chemistry? I'm assuming I will kind of have to start fresh after topping off. I shock at least once a week with OxySpa MPS. Should I shock again after refilling? Thanks!