One thing is reading it and the other is knowing what to do.
EC is the direct measurement of the electrical conductivity of the fluid. PPM is the calculated part per million of ionic salt concentration. The problem with that is the conversion factor. Someone here just mentioned 0.7 but there is also 0.5 which we seem to use commonly in the USA. And there 0.62 for certain instruments.
And then there is calibration with is temperature specific.
So, .5 is easy. That's 500 ppm. As to how much, how far, how fast....I'm just an amateur on that. Some types are hungry some are more frugal. So, for me anything over 400 or so total ppm feels dangerous. Some guys claim they can push to 1200, 1500 or more. I have never got there. I have killed some pushing too hard.
Just take it easy. RO water with rooting hormones until you get good roots. I brew microbes and use Rhizotonic to try to support the root zone. To me now, roots are everything. And too much, too soon, rushing up the ppm is no good.
