Remster

Out of the tap my water's pH is 7.6. If I allow a glassful to sit out for a few days it goes down to about 6.6. Why?

davemonkey

Do you know what the tap water is treated with? Also, you can call your water district and ask for a copy of their annual report (or how ever often they send it out) that lists the various compounds and elements in the water.

-Dave

TAB

sounds normal to me.

my local tap water comes out at 7.6, 48 hours later its 6.9.

best guess its a combo of degasing and chemicals used to "clean" the water breaking down/ evap.

Remster

I was thinking that CO2 degassed and if that were true that the pH would rise not fall. I'll call the water company this morning.