if distilled water isn't pH neutral, how to measure soil pH?
To test your soil the recommendations I've read are to mix some soil with distilled water and then test the liquid. But recently a scientist friend (who has worked in labs) told me that distilled water wasn't neutral, that in the lab they usually found it to be around 5.5-5.8 pH.
I've confirmed this by googling around. It seems that distilled water absorbs carbon dioxide from the air and that makes it more acidic.
My el cheepo ph test strips showed vinegar at 4 (supposed to be 2), distilled water at 6.5. If they're reading high by about 2 points, that would make my Albertson's distilled water around ph 4.5 . Not much of a test, I admit, but all I have at the moment.
So what can I use to mix with my soil for a good pH test. ...reverse osmosis water, de-ionized water, home adjusted water? Any recomendations?