Greetings all!
This is my first post as a relatively new owner of a 7600 fiberglass pool (the Latham Olympia 12), with a SWG, for which construction was completed October of 2023. I am in Sacramento, California. The pool has an autocover which I've been using most of the time up to this point, but I'll probably want to use less as it gets hotter. The pool is set up to refill automatically as water is lost.
Since I took over responsibility for maintaining the pool, I have been using dry acid to keep the PH from getting too high. To date, I have added
23.4 oz of dry acid, with almost half of that added in the last week.
Yesterday I discovered the use of dry acid is "discouraged" in pools with a SWG. Specifically, the Intellichlor manual says: "The use of dry acid (sodium bisulfate) to adjust pool pH is discouraged especially in arid regions where pool water is subject to excessive evaporation and is not commonly diluted with fresh water. Dry acid can cause a buildup of by-products that can damage your chlorinator cell."
My question is:
Did I catch this in time, such that I'll be OK as long as I don't add more dry acid? Or should I drain/dilute my water to avoid damage to my SWG?
Some additional details.
I did a back-of-the-envelop calculation based a 2019 post from
@JoyfulNoise (
Dry Acid (Sulfates)), and estimate that the dry acid I've added to date increased my sulfate concentration by almost
19 ppm of sulfate ions. This is of course in addition to the baseline in my water supply. Looking at the website for Sacramento City Water, it there are 18 sulfate tests ranging from 4.9 ppm to 34.5 ppm, with an average of around 12 ppm, and a regulatory limit in California of 500 ppm. (Am I correct in understanding "sulfate ions" added by dry acid to be the same as the "sulfates" indicated in drinking water quality standards?)
So, it seems I have likely materially increased the level of sulfates in my pool water, but might still below well regulatory limits. I also noticed that sulfate levels in the drinking water provided to rural areas around Sacramento are higher.
I tried to research this question on my own, but didn't see any reliable information about the level of sulfate concentration likely to damage a salt cell.
I only want to drain/dilute if its absolutely necessary, since (1) my water is otherwise excellent condition, (2) I hate wasting water, and (3) fiberglass pools cannot be drained, so that turning over the water in a fiberglass pool. But I'm willing to do it if its my best course of action.
Does anyone here have thoughts on this, or a recommendation for me?
Thanks in advance!
Galen
P.S. I hope this question is appropriate for the "deep dive" forum, but my apologies if there was a better place to post this.
P.P.S. I've been using the TF-100 kit to monitor my pool water. For reference, my most recent levels were: FC: 2, PH, 7.9 (after adding a bunch of dry acid), TA 80, CH 200, CYA 30 (need to increase this), salt: 3800, Temp 69 F, CSA -.18. I don't think this is relevant to my question.