New to TFP

[wjr75]

Hello All,
First I would like to say that this site is great! Just bought a FT-100 and ran some tests listed below. I live in IL and have my pool drained/power washed and acid washed before filling every spring.

FC-4.5
CC=0
TA=210
CYA=55 ( Not sure how accurate..added 6lbs of CYA to the newly filled pool, 25k gallons)
CH=260
PH=7.5

I started on lowering the TA by reducing the PH to 7.2 and then waiting for it to rise by the water aeration. I just read this article http://www.poolspanews.com/bond-financi ... watch.aspx that states to subtract 30% of the CYA value from the TA value. Is this true? I haven't seen that stated on this site since I have been reviewing the forums.

Thanks!

 

[JasonLion]

We always use the TA value directly from the test kit and never use the adjusted TA value. The only reason to ever use the adjusted value is when calculating LSI, which has be superseded by CSI which uses TA directly, so really no reason to ever make the TA adjustment.

 

[wjr75]

Thank you for the reply. How much total muriatic acid over time do I need to add to bring my TA down from 210? Our tap water out of lake Michagan evendently has high TA.

Thanks

 

[Richard320]

Thank you for the reply. How much total muriatic acid over time do I need to add to bring my TA down from 210? Our tap water out of lake Michagan evendently has high TA.

Thanks

According to Effects of Adding Chemicals in http://www.poolcalculator.com/, each gallon of 31% MA will lower pH by 1.23 and TA by 20. So...maybe 7 gallons, spread out over a looooooong time. What's your target?

I wouldn't be in too big a hurry with the TA. It's not critical for you because the CH is not really high. Just adjust pH each time it gets to 7.8, it will come down eventually. If you get tired of adjusting every other day or whatever, then commit yourself to spending a weekend with this:
pool-school/lowering%20total%20alkalinity