Public service announcement:
Anyone who wants to test their soil pH using the runoff should follow the scientifically proven "pour thru method" outlined
here in a pdf from Cornell University.
Testing your runoff any other way is as accurate as calibrating your pH meter using tarot cards. Oh yeah, use a calibrated pH meter if you test.
For those who don't trust pdf files, here are the instructions:
Steps for the PourThru method
1. water containers to saturation (so that a few drops of water come out of the
bottom of the container) with the normal irrigation water they have been receiving
2.
after container has drained for one hour, place a saucer under the container
3. pour enough
distilled water on the surface of the container to get 50 mL (1.5
fluid ounces) of leachate to come out of the bottom of the container
4. collect leachate for pH testing
5. calibrate pH meter
6. measure pH of samples