Molasses serves more purpose in the budding stage than it does the vegetative stage... just my opinon. Humidity is fine @ 36%. Rockwool cubes hold a ton of water in my experience man, I wouldn't leave a half inch of water in the tray. I'd just keep the cube wet / moist.. with seedlings in rockwool I could go 3-4 days without watering.. the stuff has huge water retention. Molassses is also useless without mycos. No mycos, no point in molasses. Plants can't use sugar in it's raw form. None of your nutes are myco innoculators. Therefor you'll get 0 use from molasses and just gunk up your rockwool at this point. Your
OF soil though, that's gonna have mycos in it and get some benefit from molasses.
I just see