High pH / Low TA

[contactmypics]

Hi everyone.

I've owned my Bullfrog A7L (440 gallons) spa for 2 years and continue to have water balancing issue(s).
The tub is equipped with ozone and uses the Frog system (minerals + low chlorine).

Recently did a water change and using a Taylor kit had the following readings:
TA 120
pH 8.0+

I have so far added about 5 oz of Clorox brand pH Down over the course of one week (adding 1Tbs per day... sometimes 2Tbs if i start early enough in the morning and the reading is still high in the evening).  I usually wait 12-24 hours between readings / adding more pH down.

My pH is still reading 8.0+ but, as would be expected, my TA has dropped to 60 (which i believe is too low, and even if borderline low it will only get worse if i continue to add pH Down).

I have not yet installed the Frog system cartridges, or added the pouch of shock(?) that comes with it, as the instructions indicate to get the water balanced first before adding the cartridges.

We are not currently using the tub; we would like to, but trying to first get the water balanced before introducing another variable.

In my previous years' experience if the water is not properly balanced the Frog system is ineffective at sanitizing (ie- chlorine levels would be way too low, even for the frog system which is supposed to have low chlorine levels).

Thanks for reading and for any advice/suggestions.
 

[Sid]

To drop pH I add Muriatic acid (diluted about 1:3 in water). An ounce can drop the pH in my 240gal spa >1pH point. The major difference between what I do and what you do is that I retest pH about 15-20 minutes after adding the acid, and continue adding as needed, adjusting amounts added as I get closer to my final desired reading. I rarely use a full ounce, usually I'm just trying to drop the pH from ~7.8 to ~7.4. I always adjust TA first, then pH.

Edited May 8, 2022 by Sid
grammar correction