New pool Owner Pool Chemistry Question

[eyedoc89]

Hi all,

I am new to pool ownership and maintenance and I have a question regarding adding muriatic acid to lower pH and alkalinity. The TA was very high (over 200) and the pH was over 8 when I began. I have been adding muriatic acid in small doses, and there has been a reduction in my levels, however I seem to have run into a stagnant measurement. I cant get the pH lower than 7.6 and the TA is still about 180ppm. I have added nearly 3 gallons of muriatic acid so far and I am concerned about adding too much. Any suggestions? Thanks for your help

 

[zea3]

Hi, welcome to TFP! Is the pH still trying to climb? If pH has stabilized at 7.6 with a TA of 180 it will not harm anything to let TA stay at that level.

 

[eyedoc89]

I think you may be right about the pH stabilizing. Its been 7.6 for a few days now and my acidity demand test keeps indicating that I need to add more muriatic acid. (about a quart for my size pool) I want to add CYA as its getting hot and sunny here in NV but I was hoping for the alkalinity to be better. Should I go ahead and add the CYA anyway? Thanks for your response.

 

[frustratedpoolmom]

Hi all,

I am new to pool ownership and maintenance and I have a question regarding adding muriatic acid to lower pH and alkalinity. The TA was very high (over 200) and the pH was over 8 when I began. I have been adding muriatic acid in small doses, and there has been a reduction in my levels, however I seem to have run into a stagnant measurement. I cant get the pH lower than 7.6 and the TA is still about 180ppm. I have added nearly 3 gallons of muriatic acid so far and I am concerned about adding too much. Any suggestions? Thanks for your help

Is this a new, plaster pool?

 

[Richard320]

Welcome, Doc!

Don't hold off on the CYA. As a bonus, it's a mild acid, so it could shift the pH enough to notice.

A couple of thoughts:
1) If the pool is under a year old, curing plaster will keep pH and TA climbing and you'll use acid at alarming rates. It's normal.
2) The pH tester maxes out at 8.2, so it could well have been 9. And since pH is logarithmic like the Richter Scale, it will take ten times as much acid to get from 9 to 8 as from 8 to 7.
3) If you want to lower TA faster, adjust pH down to 7.2. The Carbonates outgas as CO₂ faster at lower pH.

 

[frustratedpoolmom]

Yes add the CYA