straightpipes...Mums must be at least a month old. I suggest waiting until you have vegged Mum 2 months.

Mister source...just strip some black plastic dropcloth or trashbags (the thicker the better, easier to deal with during application...) and duct tape it around the tub until light can't get in. Or, 3 wraps gray duct tape all around, or 2 wraps of black duct tape.

Head what advice Zandor gives you. This is very important
why do you think all hydro gardens are opaque? Think about it.