those meters really suck, your way better off with a cheapo chemical PH test kits from the pet shop for aquariums

get it ...test the ph of your water and complete a soil runoff PH test.......
with PH corrected water (6.5-6.8PH ) pour enough water in the pots so the water runs out the bottom of the pot ...collect & test the PH of this runoff water....post both the watering going in the pots and the runoff ph

watch this video I made

http://ganjaguerrilla.net/PH%20&%20Flushing.WMV
Ganja Guerrilla Reviewed by Ganja Guerrilla on . why is this soil plant droopy using a soil mix organic blend with peat(1cu), and perlite(small bag) all plants are fed the same with a GH3 @ 1/4 stregnth everyother feed after leaves started to yellow(water, feed, water, feed)every 3rd day the sl has always been droopy and the 2 sk have not a week just got a cheap soil ph meter and ph was about 7.5 3 days ago i bought a iron + soil acidifier(directions say use 2/3 cup to large bush to correct from a ph of 8 to 6.5) Rating: 5