I never knew what good a PPM meter would do until i got one and used it just for shits and grins. I'm curious as to the ppm ranges necessary, or, are most beneficial in a soil/hydro system. I get my water from one of those windmill water stations and it test at 11 ppm. I mixed my amendents per gal. just to get a reading. CalMag alone, at 5ml/gal gives 240ppm, 7.5ml/gal - 340 ppm, 10ml/gal - 450ppm. Which level is best for early/late veg, early/late flw? Also the fets. FloroNova gives ppm near the listed ranges but my plants keep showing deficiencies and have wild ph fluctuations when i start at 6.2pH. I have a white widow (soil) that's 5 wks into flw and looks the same as it did at 3 wks. A white rino (soil) that's 6-1/2 wks and full of rusty spots. The twisted thing is that both plants get the same fert mix. What's the best ppm per amendment and at what stage for a soil mix and hydro? And what about adding hydrogen poroxide to the solution? Somewhere i read that the extra oxygen atom helped in a soil mix. Dose it do any good in hydro or does it do any good at all?