Eh. I ended up springing for a BlueLab EC meter.
I have two cheapo ones and they were both reading within a few points of each other, but who knows.
If everyone here thinks that we're looking at ~.26EC per gram, that works for me to calculate where things are. My water is a bit of a mixed bag since some times of year it's ~220ppm and other times its closer to 300PPM, etc. I usually discount my water's native PPM/EC since I don't think much of what it carries to be bio-available (As proven by having calcium & magnesium deficiencies when I'm not being super careful).