I thought so,...:check: ..... yes, if you make an effort to spray just the leaves, and don't totally soak the entire plant... it'll take some effort, but going foliar is, again, the fastest way to get it in there! ...and mind what I suggested about when to spray,... make good and damn sure she's dry by lights out, just to be safe, mate! do you have a liquid Ca-Mg? ..lots of choices out there; I'm using General Organics, with great results on my problem MoB, outside... It's a great supplement just to have around regardless, as Ca-Mg issues are common it seems with autos, and others too... I dilute mine to about 1/2 strength, and treat at least twice over a few days; as for your nutrient media, follow directions unless others here say otherwise,... I double checked the pH charts in Rosenthals' and Cervantes books, and 5.8 in hydro is okay, but it seems the chemistry of this type of system has Ca at suboptimal availability at what is considered the best overall pH to be at, so maybe that's why it cropped up like this... flowering places enormous demand on the plants' resources, so nute's that are shakey to begin with get depleted quickly when there's a jump in demand... Oh yeah, the water spreader is excellent for anything you spray, nutes, bug killers, whatever! :thumbs: ...Get jiggy bro'!