Question about balancing TA & pH

Fronzizzle

Well-known member
Jun 29, 2017
79
Augusta Township, Michigan
Hello all,

Some quick background: I opened my pool last week, did a SLAM for 4-5 days and have it looking great - no CC, water is crystal clear, very little debris not the bottom (have been doing a quick vacuum every 2 days since the SLAM ended).

An issue I posted about when I opened it was that my CYA was reading 0, even though it was high all last year. My test kit wasn't old but most of the reagents were expired, so I ordered a new one (the TF100) and proceeded to add 20 ppm of stabilizer via the sock method.

The pool looks great and the chlorine levels seem to be behaving normally, but my new test kit just arrived and I did some testing. It's hard to get the hang of the CYA test, but I think it's around 50 ppm now, not the 20 or 30. Not a huge deal, just odd (or maybe not, if the old reagent was bad).

My question comes in via the pH and Total Alkalinity. Last year, I noticed that my pH was drifting up and I was adding chemical (I use the HTH pH Decreaser product) every week to keep it in the 7.2 - 7.6 range. Using the new kit, I just tested it again and my pH is high (around 8) and my TA is also high, 150 ppm.

If TA is supposed to between 80-120, I need to lower it at least 30 (ideally 50) ppm. How do I do that efficiently? The pH Decreaser says that to lower the total alkalinity by 10 ppm per 10,000 gallons, to add 2 lbs. My pool is 13,500 gallons, so I'd have to add like 8-10 lbs. of it. Is that a good idea? What would that do to my pH?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
30,848
Laughlin, NV
Just let the TA come down as you keep the pH in the 7's. No reason to lower it quickly unless you find your pH rising very quickly.

Be aware that dry acid adds sulfates to your water. They can build up in the water. It is best to use muriatic acid. But up to you.
 
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