TA Recommendation Change?

gregsfc · Apr 20, 2016

Last year I came upon a discovery through the help of experts on here, that has helped me mange pool care much easier and faster and cheaper. I later found that I was not alone, and there have been some other members come to this same realization due to the characteristics of our pools that makes us have to manage it slightly out of range on one of the levels. This has been a real work and product saver, and it's taken me from a TFP subscriber that did not have a trouble-free pool to one who does. What was happening, not being very chemically oriented in my head, and therefore not having a full understanding of the "whys", I was just simply taking all the recommended levels as the bible on pool care, I was trying to keep all my levels in check and adjusting as religiously as I could to keep all the levels in the recommended ranges. It was, however, anything but trouble free. With everything in balance, the PH would creep up out of range about every two days; I'd add the recommended acid and keep going. I got really good at knowing my pool and exactly how much to add to get the desired effect. About every two weeks, just as pool math would suggest, my TA would drop out of range due to the continual additions of acid. And then, being a good student, I would immediately bring the TA back between 70-90 with soda.

I finally took to the forum asking if it was okay to let my pool drift up and stay at or about 8.0-8.1, because it seemed to quit drifting beyond that point, and I had found that the originator of the BBB method on another site had written an article claiming higher PH was okay for pools that sort of equalized at that higher level. What I didn't know at that time, because again, I'm not chemically minded, was that another parameter, the TA could be allowed to fall below the 70 level to solve this whole problem.

The remaining problem for me is that, even though I've read over all the CSI stuff and out gassing stuff relating to why some pools are different and need lower TA levels to stay in balance, I'm still having problems understanding all these numbers and how they work together.

I opened my pool and everything except for FC was in range; ph was on the low end of the range, but still in range. FC was a little high. In late Fall, when I closed the pool I shocked it and closed it as per TFP instructions. I don't know if maybe I over did it a little or what, but I expecting to have to shock the pool or at least add some bleach when I reopened, but in reality, I'm having to let the sun consume some chlorine before adding. Three days later, I've got something new I've not had since the pre-TFP days when I was using trichlor pucks w/o reservation, and that's low PH. Way low. I've checked in twice in two days, and it's at or near 6.8. Unlike in those pre-TFP days, this time around I've gone out and bought some borax. I added 34 oz by volume and will recheck today. It should put it up to 7.2. I'll recheck and add if necessary.

Pool Opening / 3 days later
FC 7 / 4.5
CC 0 0 / 0
CYA 31 * Did not retest but tested 3 times on day one and got a consistent reading just above the 30 line before the water clouded to the point
TA 50 50
CH 250 * Did not retest.

First question: I figured this would be a good time to go back through pool school to make sure I still know what I think I know about pool care. That's when I noticed the recommendation for TA has changed from 70-90, to 50-90 for vinyl pools. Does anyone know what brought about this change. I know that's much closer to making my pool work, as I had to let mine go down 40-45 to keep PH in balance.

Second question: Not being chemically minded, how is adding these borates going to effect this equation, as I've read they can add some buffering? Should I just sort of hang on until I get the PH in range and see what happens and maybe my new equalized TA will be a little different or something else?

Third question: What in the world would cause my PH to crash after opening. It dropped actually on day two from about 7.3 to 6.8 in one day. I've let the pump/filter run, after backwashing on low for the first 24 hours. I tested twice with the same result regarding the low PH. I didn't have anything to raise PH except for aerating, so I aerated a little and let it go. I tested again on day three with some borax on hand. It again measured 6.8. I added enough borax to raise to 7.2 as per pool math. Though I'd raise a little and recheck today.

Any advice is appreciated. This is a new phenomenon to me.

Thanks in advance to the experts on this site for what you do.

pooldv · Apr 20, 2016

Congrats on maintaining your pool TFPC style!

Yes, we are modifying recommendations on TA. We are continuously updating and working to improve all aspects of pool care through our own real world tests and experience and the observations of thousands of other pools.

Your PH likely crashed because your TA is a little too low. It seems that TA of 50 ppm is about as low as you most folks should go. I recommend that you set your TA at 50 and monitor your PH. If it still rises then add borates. Or, if you want borates go ahead and add them when you get your TA to 50. I am a fan of borates in my pool.

More here on raising TA, Pool School - Recommended Pool Chemicals

And more here on borates, Borates - Why and How

CLICK HERE to Become a TroubleFreePool.com Supporter!!

gregsfc · Apr 20, 2016

It was a long post, but my TA is already currently at 50, even though I had hanging around 40-45 last year before it was low enough to keep PH in check. Fifty is just what I opened up to and I didn't lower it of course with this low PH thing going on. After adding the borax, which should have been enough to take me only to 7.2, it came back 7.5, so it's a good thing I just added a small adjustment as recommended in TFP instructions. FC finally dropped to 3, so I added a small amount of dichlor to raise FC up 2 and start easing up CYA, since I'm @ 30 and would feel more comfortable around 40, but have a small pool and don't want to buy a bunch of CYA that I won't use. I'm going to see how everything goes at this fifty-ish level. Something might be different this year and I may end up with a more normal TA level.

I'm not really adding borax for the borates. I bought it for raising PH. It's just not something I've ever had to do or use, and just wondered if the small amount of borates that got added would affect what TA level or anything else.

Thanks!

I'm checking out the supporter site. This site rocks!

chiefwej · Apr 20, 2016

When you raise the pH with borax, the TA will also go up. The TA goes down as you lower pH with acid and up as pH rises, (except when the pH rises due to aeration). You lower both pH and TA with acid, then raise pH (without the corresponding increase in TA) by aeration, then repeat the process.

woodyp · Apr 20, 2016

I played with it last summer and my PH is more stable at a TA of 50 to 60 vs. 90 I used to be at.

pooldv · Apr 21, 2016

I did some reading on PH and TA. Even with TA at 50 adding anything that is net acidic can cause PH to crash.

Here is an interesting read if you find this stuff interesting, Relationship beteen pH and alkalinity

gregsfc · Apr 24, 2016

Thanks for your help. I may consider borates later on, but I'm not sure I want to do all that aerating and such, at least at this point in my life. I re read the linked thread you posted, which I had actually been involved in back then, but did need to re read it, because I don't understand a lot of the chemical part of it. However, after re reading it, the lessen I got out of it was the exact opposite of what you're saying, which is basically, if my pool has excessive outgassing for whatever reason, one method is to let the TA equalize a little lower, which is what I have done, to keep PH from drifting up. I can't remember exactly what Chem Geek asked from me, but he helped me on another thread. Needed to know my CH, CYA. He then calculated how high my TA would have to be in order to be resistant from crashing. My number was in the 30s and I'm not getting under 45 or so.

Keep in mind, since going to the TFP method, this is the first time I've ever had low PH and after adding one dose of borax, the PH is holding steady at or about 7.5 for days now. That was the reason for my inquiry. I wasn't familiar with any kind of PH up and wanted some understanding. I'm currently daily dosing a slightly acidic form of chlorine at this time in dichlor to raise my CYA w/o buying CYA. Adding the borax, as you say, should have raised TA by 8. I've not retested my TA. I'll test it on my weekly round of tests, but I suspect it's no higher than upper 50s.

I'm just wondering if the debris in the pool (almost all pollen and old dried up oak leaves) that came off the trees and in the pool, through the cover somehow when the new sprouts grew out on the trees. I wondered if that debris being stirred up with the pump/filter, vacuuming and brushing could have been the cause of the PH drop 1 day after opening when everything was in range on day one; and this was before adding anything.

Anyway, looks like I'm good for now. PH holding steady.

Thanks again.