New owner and new to testing and balancing, ?'s on plaster coating and CH

Jul 29, 2016
1
IL
Day1
FC 1
CC .5
TC 1.5
CH 425
TA 300
CYA 20 or 25
pH 8.2

Note my testing methods are prob not up to speed yet so may have wobbly numbers from my inexperience. Added 1 gal 12% Chlorine, 1 gal MA, and 4 lbs CYA. The CYA went straight to the bottom so then I ran the Kreepy Krauly into a leaf bag cylinder and dissolved it that way.

I had been running tablets in a Hayward puck feeder for about a month prior to getting the TF test kit 5 days ago. It was a fresh fill after pressure washing and re-coating the plaster with a product called Thoroseal (somewhat gritty whitewash rolled on like paint but wetter, containing portland cement, various calciums and other stuff and a latex binder) Following previous owners method of opening (water never reused) since we have abundant well water and easy disposal. Maybe the high CH is from that coating?

http://www.thoroproducts.com/pdf_msds/MSDS Super Thoroseal.pdf

Day2
FC 17
CC 0
TC 17
CH 425
TA 300
no CYA test
pH 7.5

Added 1 gallon MA, no liquid chlorine and had Hayward puck feeder turned off.

Day 3
FC 18.5
CC .5
TC 19
CH 425
TA 260
CYA 60
pH 7.2

No MA or liquid chlorine added, but wondered if the feeder was not really closing its valve, may have been a trickle still coming from that, so I rinsed it clean and dropped the small amount of solids from it into the skimmer to dispose of it, about one puck worth of white stuff. So I know the feeder is empty now (and was likely running even when the dial was off), and most has dissolved in the skimmer. At end of the day I drained a few inches off the pool from recent rains.

Day 4-one hour ago
FC 21
CC 0
TC 21
CH 400
TA 250
CYA 50
pH 7.5

FC still climbing with not much chlorine added, whatever was in the fragments dropped in the skimmer is all that was added. CH, TA, CYA are coming down, maybe from the rain dilution?

I tested the CH of my garden hose and it was 150, so is the CH likely to be coming from this plaster coating I used?

I guess I got the CYA at a good place, but does the CH and TA matter much on a practical level?

The pool math for CH is calling for a 56% drain and fill and that seems wasteful at this point.

TA at pool math says to lower the pH to 7.2 with acid and then raise the pH with aeration, and it has zeroes in the boxes for adding soda. I guess I am not wrapping my head around that yet. Seems like a strange instruction.

Pool math is calling for most of a gallon of MA to get to 7.2 pH but I would have to go out for it and not sure if my hardware store is open today.

Thanks in advance for any tips the forum has, I have enjoyed reading here.
 
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What pool math is suggesting is to lower your TA to help with PH rise. Pool School - Lower Total Alkalinity

Acid lowers TA and aeration raises PH. Your TA is very high which will cause your PH to rise quickly. Lowering your TA will slow the PH rise. So to lower TA is a process of adding acid and aerating to bring PH back up. That is how you eventually get TA down.
 
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