pH always high

[Drsweet]

I have concrete pool with a SWG. The pool is 2.5 years old now and I have always had a stuggle with the pH. I use better than a gallon of muriatic acid a month. If I don't add acid once or twice a week, I don't know how high it would go. I have come back from vacation and it has been over 9. This is not my first pool and I have followed the TFP process with all of them. I have just never encountered this problem before. I have a fountain in the pool but it only runs 2 hours a day. I keep the CH at 350. No problems with FC (until this week but that is a different story all together. I think my SWG is dying). Any ideas on what keeps feeding this perpetual high pH?

 

[mknauss]

Welcome to the forum!
What is the TA of your fill water and do the acid additions more or less coincide with your adding that fill water to the pool? What TA level do you maintain the pool water at? How are you testing the pool water chemistry?
I suggest you read through Pool Care Basics - Trouble Free Pool and even look at a few of our videos TFP-TV - Trouble Free Pool

 

[Drsweet]

Thank you for the reply. The fill water has a TA of about 100. I have an automatic filler so it is tough to say although I do have to use a little more acid in the summer which may be accounting for that. My target TA in the pool is 70 and it is never high. I occasionally have to add some baking soda to it. I use a Taylor k-2006 kit for testing (I use an Apera pH probe as my pH is ALWAYS above 8 when I test it). I will spot that the fill water TA is high but it seems like the acid requirement is excessive for the delta between fill and target TA.

 

[mknauss]

You should never need baking soda. Let the TA come down to 50-60 and see if the pH rise stops. Never lower the pH below 7.6 using acid.