Raise PH of soil? Is run off actuate reading of soil PH? One of my plants might be getting sick, I need a fix for this ASAP!

no, it's not accurate.. it tells you the direction it is going.. realtive information only. so, if lower on runoff, you can assume it's even lower in the soil fairly safely, but i wouldn't venure to guess how much. it's a logrithmic scale, so it takes a lote to drop 1 pt on scale and more each successive drop. Garden lime will raise it, but maybe not fast enough? if it happens again, add instructed amounts when you mix the pots relative to soil volume. alkaline water will be temporary and impossible to guesstimate with accuracy what you need. maybe, give them 7 and not push it for now. Do you fertilize every irrigation? if so, don't do that in soil. sorry if basic, but .. it's possible and could be part of the cause of pH imblance.