Rather than using a "bubble tray", perhaps you could consider using ebb and flow to get your girls root structures big enough then switch your e&f to a "bubble tray" right before transfer to the UC. I do E&F for about 3 weeks or so then transfer them to my UC 4 banger hot rod with a top feed ring for another month of training and bondage before flip. The only real way to get the full benefit of the UC is to veg in a more gentle system until your roots are adequate for the UC. I find that the stall is almost non existent this way and it give the least amount of stress for a smooth grow. Now I may fuck up the garden by pouring gasoline in the epi, but never from a bad transplant. Best of luck.
