I have a little el cheapo pH meter... a RapidTest analog unit. Someone told me all they actually do is measure the pH of the water you mix with the soil sample, not the pH of the soil itself. I was looking for a fast, cheap way to get a rough estimate of soil pH, but I'm not sure about this. I've tried using both distilled water and tap water. I know my tap water has some buffering agents in it, but there was no difference in my test results. I get 6.8 either way. Adding a couple of drops of lemon juice spikes the pH way down, and a few granules of Epsom salts spikes it the other way. I'm waiting for my lab soil test to come back for a cross reference, but in the meantime got another cheap pH test kit. This one comes with a small plastic test tube and a capsule (also RapidTest). Mix the soil, water, then add the capsule and check the color. Same approximate result: between 6.5 and 7.0. I kept this tube for over a week, and the color never changed. Does anyone know what technique the labs use? Is this meter worthless, or can I use it for rough guesstimations? Is there another inexpensive way to get fast pH results? TIA!