I'm merely a parrot here........my hydro guy says you can check runoff and determine IF you need to flush by the numbers (he says he usually will flush with a number around 900ppm) and then AFTER flushing he likes the ppms around 300 so Reaper you don't try to be as exact with it as with hydro. My understanding of this is that its much more for overnuting than ph in this case........but he SWEARS by it.

I agree Stink.....most soil growers DONT have e.c. meters to measure that stuff with. And while YOUR eagle eye (and eagle tongue ) may be able to see when something needs flushing etc....NEWB soil growers like me need all the help we can get.