Join Date: Jul 2010
Location: Outside Philadelphia, PA
The first thing I'd check is the pH test solution. It may be bad. If you truly made a 5 dkh solution, you should have a result of it being blue, not dark green.
I generally only add the pH solution when I'm actually filling my drop checker. I only need 1 drop, but that's a very small amount of water.
BTW, it's generally useless to test pure distilled water. With nothing in it, the pH reading from a test kit or even a pH meter tends to be all over the place.