Low TA, high pH

[vanessadickson]

Hi there! I have a new issue this year Ive never had....low TA with high pH. Im a faithful TFP follower, having used the TF test kits for several years, so Im sure my numbers are right:

FC: 8.5
CC: 0
pH: 7.9
TA: 50
CYA: 40
Salt: 3200
Temp: 72

Ive been dealing with pH creeping up by adding muriatic acid as needed (weekly, bringing it from 7.8-.9 down to 7.5-.6) but afraid to do so now with the TA so low. Also afraid to raise the TA with soda bc I dont want to pH to be higher. Help?

PS-posting our new pool shape and decking we put in last year, bc. Im proud of it

35,000g, UG, vinyl liner, SWG, Aquabot TurboT, TFP 4EVER.

 

[Texas Splash]

You should be proud of it. That sceniery is gorgeous. At some point you'll have no choice but to increase the TA a bit so that you have wiggle-room to use acid on the pH. You don't want to go any lower than 50. I'm going through that right now as well. Just go slowly and in stages with the baking soda. If you only increase the TA by 10-20 ppm, you should be able to continue working on the pH without it going through the roof. In addition, the slow/consistent acid treatments should help bring the pH down slowly without effecting the TA too drastically.

 

[mknauss]

Wait until your pH is solidly an 8 before adding acid. Then lower only to 7.6

 

[vanessadickson]

Thanks guys, that is good advice and makes sense to me. So Pool Math tells me that I should add 10lbs baking soda to increase TA from 50 to 70. When you use the “effect of adding” function, it says will increase 50 to 70 and will have 0 impact on pH. (Huh??? I must have missed that part of chemistry class!)

My plan is to add 5lbs, see what happens, then add the other 5 later on if all goes well. Then check pH, if its a solid 8 correct to 7.6 with MA.

You guys are the best ?

 

[mknauss]

Baking soda should have little effect on pH.

 

[gorocket1981]

Am I correct? Baking soda will rise TA but should not affect pH so any regular baking soda will do the job to raise TA and do the same thing than the Alcalinity+ stuff sold in pool section of hardware store or pool store? Is that correct?

 

[mknauss]

Correct. You should be able to get large bags of baking soda at Walmart or other big box type stores in your area.

Could you be a bit more specific on your location? Canada is a relatively large area.

 

[gorocket1981]

Ok thanks. I am in Montreal. I will go in my profile to check to add the detail.

 

[vanessadickson]

Do you think adding borates to my pool would help stabilize the TA/pH issues in the future? Ive bever really considered it bc my pool is merrily rolling along with few problems.

 

[jtpipkin]

I don't want to tell you borates were a magic bullet, but since I've added them, My TA and pH have been rock solid stable. Might be the TFP method too, as I'm new at all this, but can't believe how boring my pool is now to take care of...

 

[Yakhack]

I also have had low TA and high ph lately as I've transitioned from pool store screw ups.Last nite had TA 75 and ph 7.6.The TA has been trending down and PH up.20K plaster pool , have been playing yoyo with 4 # bicarb and acid.last few weeks.This morning dumped 8# bicarb in deep end for 4hrs before filtering came on.7 hrs later TA is 120 and ph 7.8. Past experience tells me that next week T/A should be around 90-100 if I keep ph at 7.6 with acid ,hopefully that will stop the yoyo.I got to thinking it was better to make a big jump to get past the up and down.8# should only take me up apox 25ppm.I am using alot of liquid cl to sanitize as my cya is high also,that may be raising my ph a little.Time will tell.

 

[mknauss]

.Last nite had TA 75 and ph 7.6

There was no reason to add baking soda with those numbers. You are causing the yo-yo by raising your TA so high. Let it settle at what it does by keeping the pH at 7.8 or 8. As long as the TA is 50 or higher, no issues.

 

[Yakhack]

Okay --thanks. Now that I'm managing water I guess I was like a kid in the candy store--trying it all.Thats good to know, perfection is not necessary,.... I'm good at that.Lots of practice on that front.

 

[JF July]

There was no reason to add baking soda with those numbers. You are causing the yo-yo by raising your TA so high. Let it settle at what it does by keeping the pH at 7.8 or 8. As long as the TA is 50 or higher, no issues.

Thanks! This answers my "ideal TA" question. Mine seems to stay right at 60, and I wondered if I should try to raise it to 80 (per my Taylor test kit.) So i'll just keep my hands off unless it gets below 50!