Good morning folks. Could someone explain why the P.H is 9.0 after changing the filters om my 4 stage R/O unit. It's 8.2 at the tap ! I thought it should be in the region on of 7.0 after going through the R/O. Any ideas please ? Thank you.
That is it. As you move towards pure H2O (rather then the dilute solution of salts with H2O as a solvent that we call "water") pH becomes <"both less stable"> and more difficult to measure. The problem is that pH is both a <"log base 10 scale and a ratio">.In conclusion, you can't really measure pH reliably in deionized water (which I assume your 4 stage RO unit will deliver). You need a bit of pH buffer as Darrel mentions above to make that work..