Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
So there is something adding KH to the tank.
If the source water is 1-2 dKH, and the tank is 10dKH.
Wonder what that is?
And the pH is really low, for such a high KH.
I would re-test the tank, see if that one (10 degrees) is a mistake.
ADA products usually remove the carbonates, leaving the test to read zero, and the pH can then be controlled by other things in the water.