New pool - having problems with pool math for pH

[iamtexmax]

Have a new pool - this morning pH showed 8.0 - pool math told me to add 5.3 oz muriatic acid (bought from Home Depot - 31.45%) to bring it do 7.2 - I added it in the morning and brushed the pool - just now - checked readings again - pH was 7.8....am I doing something wrong?

 

[mknauss]

No. New plaster raises your pH quickly. Keep adding MA to lower your pH.

Monitor your TA.

 

[Jimrahbe]

Have a new pool - this morning pH showed 8.0 - pool math told me to add 5.3 oz muriatic acid (bought from Home Depot - 31.45%) to bring it do 7.2 - I added it in the morning and brushed the pool - just now - checked readings again - pH was 7.8....am I doing something wrong?

Or... I show to go from a pH of 8.0 to 7.2 means you need to add about 52 oz. of MA, not 5.3 oz which only drops your pH by .08 or from 8.0 to 7.92..

Thanks,

Jim R.

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I was just using the "Effects of adding chemicals " section...

 

[iamtexmax]

Thanks Jim, mknauss - I also think I am getting the MA quantity wrong - but rechecked pool math - attached pic (I had put pool as 15,500 gallons) - what am I doing wrong? I bought the Muriatic acid from Home Depot - says 31.45% on box

 

[mknauss]

Be sure your pool is listed as 15500. No comma.

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You also need to have a TA input into PoolMath. It is needed to correctly calculate acid requirements.

 

[iamtexmax]

Thank you sir - added TA and showed me 35 oz of acid needed