i wish u the best of luck... organics and dwc have never gone well together from what i've seen around all the boards on the net... the high levels of dissolved oxygen in the dwc setups wreak havoc on the oganic nute compositions creating all sorts of ph flux and whatnot.

is cal-mag organic? if not why continue down ur path? u paying for electricity or just playing around with some plants u don't care much about? i've seen a lot of dwc go bad late in flower; real bad; entire crop go bye bad... sucks but it is a risk u take when u play with dwc; not forgiving at all

that being said i've had success innoculating my dwc system with a couple cups of freshly brewed earth worm casing tea with no ill effects on the crop; great for the first few weeks while u build up the water culture in ur dwc; sorta like an aquarium