Newbie Struggling With Balancing Chemicals

[rob137]

I have a place in the mountains that I rent. It has a hot tub and the rental company pays someone to come out once a week and check on the chemicals. I didn't/don't trust that this is being done properly. So I was up there this weekend and took some water to a spa store for analysis. They basically said to dump the tub, refill and bring back into balance. I picked up a taylor test kit like the one I used to use with my pool. I have trouble reading the strips.

Anyway, I dump the tub and refill. An analysis of the water indicates, pH 8, no alkalinity, no hardness. So I look at the tables and come up with the quantities to push the results toward pH 7.6, TA 100 and 200 CH. I put in dry acid, baking soda and calcium at basically the same time and then turn the spa jets on to circulate.

A couple hours later, I check again and the TA is around 110, CH 200, but pH remains 8. So I put in more dry acid, wait retest. pH is still high, but I have dragged down the TA to around 70 or so, CH still 200.

So more dry acid, wait retest. same results, but now I'm getting nothing for CH. The water looks crystal clear.

Check again this morning, pH is 7.8, TA 80, but no CH, put in 8 oz of hardness increaser (300 gallon tub), check again in an hour, still no CH.

Help.

[Roger]

Don't worry about the CH. Your PH and Alk are pretty close. Give it some time. What sanitizer do you use? Both Chlorine and Bromine additions over time will drive down your PH.

[Spa_Guru]

If you have overdone your sanitizer (chlorine or bromine) it will mess with the colors of your test.

None of the chems you mention can change calcium levels.