C
Carl Carlson
Testing the run-off PH is a good way to figure out the PH of the soil as well right?
Kind of.
You don't test the runoff from watering with fertilizer. Feed your plants first, water to saturation, than wait 30 mins to two hours and pour a small amount of plain, clean water through. Than you test that leachate.
fyi:
http://www.ces.ncsu.edu/depts/hort/hil/hil-401.html