Question about pH rising...

[johnd13]

I live in South Florida and I seem to have to add about a quart of acid every three days or so to keep it in the 7.4 range. Here is my last water test results:

FC-6.0
pH-7.8
T/A-130
CH-320
CYA-70
Temp-88

Water is clear and I have a spa that spills into the main pool for aeration. Is it normal to have to continue adding acid at this rate to get the pH down in the 7.4 to 7.6 level?

Thanks in advnce for any input.

 

[frustratedpoolmom]

If you keep adding acid, which will also lower the TA, you should eventually get the TA into the 70-90 range and see more stable PH.

Your TA is higher which is why the araetion causes the PH to rise frequently. You don't want to add any TA increasing products like Baking Soda.

You can simply add acid as you have been doing, every time the PH creeps up to 7.8 lower it to 7.2. Don't add anything to increase the TA, and it should lower into range eventually. If you want to speed the process up, you can follow the instructions for Lowering TA in Pool School.

 

[Butterfly]

Is it normal to have to continue adding acid at this rate to get the pH down in the 7.4 to 7.6 level?

Yes, it is normal. You have aeration from you spillover spa and a little high TA.

Eventually, your TA will lower based your MA additions and the pH rise will be slower.

You could do the "How to Lower TA" in Pool School as FPM mentioned, but you will get there without that anyway.
It will just take a little longer.

 

[Guest]

How new is your pool? If the plaster is not over a year then a high acid demand is normal since the plaster is still leaching alkaline material into the water in addition to your high TA and constant aeration.

 

[PaulR]

That's not it; OP's sig says "Pool built in Spring 2004." Must be just an artifact of the high TA and aeration.
--paulr

 

[johnd13]

Thanks everyone. Sounds like I will eventually get there

This is a great resource. I had been wandering aimlessly for the last 4 years without a clue as the water was clear and every once and a while I'd add a bag of salt. It was not until my SWG cell acted up a couple months back and I ran the salt level up to 4700 due to a bad reading that I started looking closer at my testing. The people at Leslie Pool kept telling me to add a quart of MA and I would and the come back next week and they would once again say add a quart of MA. Then I found this place through a Google search and got a test kit and starting taking care of my pool.

 

[Butterfly]

oops I completely missed that you have a SWG.

If it was my pool, I'd go ahead and lower the TA as per instructions in Pool School.

Pool School has an article for Water Balance Tips for SWG's.

Also, here's a link to waterbear's water balance tips for SWG's which has more info.