Well, if someone more experienced than me says to do something, you do it I'll look for it next time I'm in the market for nutes.

When I mist, I make sure to spray the plant lightly; like a damp morning dew

I've heard really awful things about CFL's, but if it works, don't knock it.

If your son has a remote harness, it has the piece you need. Take the fitting that goes on the tank [you can get them at the paintball store for like, $15] and put a 90* elbow on it. Put a length of macroline in it, and turn it on ever so gingerly till it starts hissing out and doesn't stop. Put it down, set the hose above the top of your plants. CO2 is heavier than air, and will go down. Filter it through the top leaves, let it flow down to the bottom

Since you're in an enclosed growing area, maybe just turn it on for a few minutes at a time so you don't waste CO2? I dunno. Good luck mate.