Why is my TA increasing?

[mc2021]

Hi,

Over the last month my TA has increased from 70 to 120. I have not used any city water, just a little rain water. I have added about 14lbs of granular cya and 12 to 15 gallons of shock. It's also very odd that my ph has been at 7.4 for about 2 weeks. I get that cya lowers ph but I just feel like something is off. What would cause my TA to keep increasing but allow my ph to remain stable and low for my pool.

Thanks

 

[Texas Splash]

It's also odd that your TA went up that much but your pH is remaining low? That doesn't add up. TA shouldn't just go up on its own. Are you sure your TA testing is spot-on?

 

[mc2021]

I've doing this for a while and always had consistent predictable results. New reagents and same bottle too. I've done it like 5 times over the past few weeks too since I thought it was odd as well. Does the amount of the green reagent affect results that much? Maybe it's clogged a bit?

 

[mc2021]

I just read the TA testing article here that suggested wiping the r-0009 bottle with a wet cloth in between each drop and now I get 100 which is where it was a week or so ago. Still don't understand the increase though.

 

[Texas Splash]

Static electricity has been known to effect some TA testing (drop sizes).

 

[mc2021]

I wanted to bump this back up and maybe get some more input. I feel like my TA test is off and I'm not sure how to verify, tests are in poolmath.

I'm getting 100+ TA readings but my PH is steady in the low 7s. Is that even possible? I've only added an inch of city water all year which historically had a TA of 120, the rest has been rain.

Any thoughts on how to validate the TA test? I'm trying to keep csi slightly negative otherwise I wouldn't really bother with this.

 

[Texas Splash]

Any thoughts on how to validate the TA test?

I'll tag @Donldson for a second opinion, but if your reagents are fairly new, you've been wiping the static electricity off of the tips, and doing the testing consistently (drops x 10) the TA should be accurate.

 

[PoolStored]

Clean your vials with rubbing alcohol and dry. Then retest.

 

[Donldson]

I do not doubt the TA test. While it's unusual to have stable pH with 100+ TA while using liquid chlorine, each pool is different and it's certainly not impossible. Similarly some people can't get their pH to stop rising even with a TA of 50.

As long as the test is being run accurately as Pat described, I'd accept the results and leave it alone. If you are concerned about your CSI then aeration will bring the pH up without increasing the TA level.