Need help getting pool in shape so I can close it....

[chem geek]

So... if I know the starting pH (and TA and CYA), what is the formula for calculating the target pH given a particular amount of Borax?

You're going to hate this answer -- it's not a simple formula. I have a spreadsheet that calculates all of this, but it is so complex and scary that it has been known to make grown men cry and teenage girls shriek in horror. If you are a real risk-taker, thrill-seeker, and can close your eyes to all the chemical equations and can live with no instructions or help, you may find this monster by clicking on the link near the end of this post in The China Shop. Don't say I didn't warn you... (HINT: Put in your Initial and Goal conditions and use the "Calculate Acid/Base/TA" button to figure out how much Borax is needed -- this will let the TA value float to match the pH you want while only calculating acid/base and not bicarb. or CO2 outgassing). (SECOND HINT: If you want to see the effect on pH of adding Borax, just put in your initial conditions and the amount of Borax you are adding in the Base section and use the "Calculate pH/TA" button to calculate the Goal values).

Richard