Do borates cause pH test to be inaccurate

[CristyW]

I added borates to my SWG pool a few months ago, and my pH tests (Taylor 2006) seemed to read high thereafter. I added borates to my spa about 5 weeks ago (stand alone LA Spas Maui) and I am noticing the same thing. My pH test consistently runs a few points higher than when I go test at the pool store. My alk test also seems to be a lighter green than without borates (but the results are the same). This makes me wonder what tests borates might alter.

I added boric acid in the amount calculated by pool math to reach 30 ppm borates. While it has slowed my continuous high pH drift (accompanied by downward alk drift) it has not stopped it. I use a floater with bromine tabs. I have checked the expiration on my reagents and just received a new Taylor 0004 phenol red, but no difference from my older tube.

Does this happen to others? Is there another way to accurately measure pH that is not affected by borates? I had a cheap pH meter, but I wasn't confident it was staying calibrated.

 

[Newdude]

My pH test consistently runs a few points higher than when I go test at the pool store

Think that through. The same water should test the same, or be similarly off both ways. Unless. The test/tester that exists for the sole purpose of selling you things you don’t need is less accurate. When they mess you up, they shrug and charge you more to fix their mistake.

Trust yourself and your unbiased (and more accurate) test.

While it has slowed my continuous high pH drift (accompanied by downward alk drift) it has not stopped it.

Borates are a helper and not a cure-all. So what you’ve seen sounds about right. As you manage the PH by lowering it, the TA slowly comes down also.

What is your TA ? You mentioned it coming down but there is a vast difference between coming down to 70, or 200.

 

[Newdude]

*another thought

How old is the pool ? If you joined close to build time you are nearing 6 months. New plaster will cause the PH to rise for 6-12 months and has fustrated ooodles of folks before you until it calms down.

*another another thought.

The PH test is invalid at 10+ FC usually reading falsely high. If you are overshooting target FC range for some wiggle room, you have to let the FC drop below 10 to get the correct PH reading.

 

[Mdragger88]

Your drop based ph test is accurate. The most accurate in fact.
Along with lowering ta, borates can help buffer ph rise but they don’t just put a halt to it especially if you have high ta fill water or a plaster pool. They are a helping hand - not a magic bullet.
The addition of borates also means you need more acid to lower ph (& subsequently ta)than you did without - which is why it is advised to lower ta to around 60 before adding borates.
Be sure you have the borate level entered into PoolMath so it’s accounting for them when calculating acid additions.

 

[CristyW]

Thank you for the advice and suggestions.

In going over all my numbers and reading your thoughts, I realized my pool numbers were reading lower on pH as well, and I've not added borates back to the pool since plastering. So there is something off about my reagent, the way I'm doing the test, their machinery, or something. My last 2 spa numbers were over 8 (my readings and theirs) so that is not helpful. I don't have the records going farther back to analyze. I just kept noticing in the past that my spa pH would be too high on my test, then the store would test and say it was in range. Since it's not a known
n issue with borates, and this past week I'm seeing in on my borate-free pool water too, I have to find another explanation!

I hope I can learn to better use the pool math app, and maybe track my own readings. I only got it a few months ago when I first put boric acid in my pool, and am used to just doing the calculations myself. I don't know enough to make more complex adjustments like how other chemicals affect Alk, and I'm bad at learning apps so I use the pool store as my crutch. They are the top pool builder in the area and honestly don't seem to care if they sell any product or not. Their advice is hit or miss, since the counter lady doesn't even know what borates are.

My pool is over 10 years old (I have had it 3 years) but was replastered 6 weeks ago. My spa is fiberglass 386 gal, and I put boric acid in it for the first time 6 weeks ago. I have always struggled to keep the pH under 8 in my spa, and settled for keeping alk at 50. I'll have to start a thread specific to my screwy spa chemistry so I don't muddy the water too much!

 

[Newdude]

and I'm bad at learning apps

The pool math app couldn’t be simpler. Get a trusty test result from your own test and enter where you are and where you’d like to be. It even has gentle reminders for target range. Then it will tell you exactly how much, and of what, to add. I’m with you that anything new is taboo. We *all* feel you. But give it a minute and you’ll LOVE it.

don't know enough to make more complex adjustments like how other chemicals affect Alk

It does THAT too. And it’s GREAT for learning. Anytime you wonder, click the hamburger menu in the upper left and then choose effects of adding. Have AT it with whatever you dream or up, or we’re looking to achieve. Seriously there are stupid amounts of combos there.

My pool is over 10 years old (I have had it 3 years) but was replastered 6 weeks ago

Bingo. You’ll have a healthy MA appetite for up to a year. You also have half a bazillion people in the ‘iS tHiS nOrMaL’ club. We meet on Tuesday’s. Glad to have ya.

I'll have to start a thread specific to my screwy spa chemistry so I don't muddy the water too much!

This is your thread so feel free to keep it here. Unless you upset yourself about it. No need to ruffle the OPs feathers.

You can also modify the title at times to attract new eyes that might know about the current asks. ‘Spa Trek III : The search for Shock’. For example. Get funky with it.