Sorry if this is a really dumb question. So I’ve been testing my PPM on my first grow and when I told my local hydro store guy what my PPM Meter read (769PPM) he asked what scale it is? Apparently different Meters use different scales (500 Scale & 700 Scale). I didn’t even realise!
So I’ve tried to find out which scale mine is and I can’t find that info anywhere! It’s just a cheap EBay Meter with very little info. I’m wondering if any of you might know what it is or how I might find that out?