Pool Calc PH

[H2O_Keeper]

I am in the process of the lower PH/Aerate technique to lower my TA. I was using the pool calculator and was trying to go from 7.5oz to 7.1oz and it shows I need 41oz of 31.45% MA. I went to the bottom to see how much this 41oz would impact the TA using the effects of adding chemicals and it shows this much MA lowers the PH by 0.47points.

0.47 move versus 0.4 move is not that dramatic, but which one do I beleive? I realize both are guesstimating due to other factors of my water chemistry but which one is closer?

 

[JasonLion]

Trust the upper pink PH section. Just make sure that you enter your current TA and Borate levels into the Now column. The upper pink PH section takes the current TA and Borate level into account. The lower Effects of adding chemicals section does not take TA or Borate into account.