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.
I will do that this afternoon when I get 5 mins .It seems very high. Have you tested the KH?
K.H is under 1 !!I will do that this afternoon when I get 5 mins .
Just add a bit of tap water (5 - 10% by volume should be fine), this will supply you with 1:1 dKH and dGH (from dissolved limestone (CaCO3)).K.H is under 1 !!
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..