TA and PH Balancing Questions

[shawnp40]

I have been using the BBA method now all summer. Works like a charm.
No more pucks; all liquid chlorine for me here on out.
My CYA is higher than I like (due to pucks) but I maintain FC pretty consistently using the TFP tables.

Pool = 25k Gallons, Plaster Inground with Spa Spillover and Waterfalls
CYA=103
FC = 8.2
pH = 8.1
TA = 65
TH = 364

I have added 36oz of Muriatic Acid each week and yet the pH seems to keep rising to around 8-8.2.

Question 1: Should I worry about my TA being low, from everything I read it should be a little higher like 70-90 thus I should consider adding 5-10lbs of baking soda?
Question 2: My pH keeps rising quickly (presumably, due to low TA and the fact the spillover (aeration) runs daily from spa). Should I keep maintaining weekly with MurAcid, or fix TA first?
Question 3: My TH is high but there is nothing I can do about it but replace water, which is probably something I should plan due to my CYA being high as well, correct?

Thanks for all the support TFP friends. I feel so much more confident with my pool these days!

 

[Donldson]

Those numbers look quite suspect. If you aren't testing your own water with a Taylor k-2006c or TF-100 kit then it is highly recommended you order one. Accurate numbers are key to good pool management.

To answer your questions:

1 - No. Typical TA recommendations assume using pucks, which are made of highly acidic trichlor. Higher TA offsets this. When using liquid chlorine, a relatively neutral pH source of chlorine, the TA has to be lower to maintain a more level pH. That's why we recommend as low as 50 TA. See the Recommended Levels Page

2 - pH rises quickly because of high TA, not low. Keep using acid and allow your TA to drop. Again though, I don't particularly trust those results.

3 - We don't really worry about Total Hardness, it is the Calcium Hardness we worry about. For a plaster pool a CH of 250-350 is good, so this number is likely well within line. If those numbers are accurate and most of that TH is calcium. I know, broken record, but reliable test results are a must for more specific guidance.

 

[shawnp40]

Yes I use a Taylor2006 kit.
And great, I will not mess with the baking soda.

I will add more acid again. Maybe my acid was old (I think I used a bottle I had left over from years ago).
The acid did not seem as effective as it should have.
I bought a new bottle today. Will add and test water tonight and reply back with results.

Do I understand correctly, that each time I add acid it will reduce TA as well?

Great information and yes all the numbers came from my Taylor kit. I took a water sample in to be sure.
They said my TA was a lower than I tested (I tested at 80, they said 65).
They said my FC was lower than I tested (I tested 10, they said 8.2).
They said my CYA was higher than I tested (I tested 85, they said 103).
pH and Hardness was same at home and in store.

Thank you for such a quick reply.