thanks, i also have them between 3-4 inchee away but that is because i am looking to get them to stretch slightly? it does make sense that having them right on top would keep them in place and not reach to growI have leared that puttin the lights to close can put the plants in a "hibernation - Hypernation (dont know how to spell it)" mode and it wont grow at all. ive had the most growth with the bulbs approx 4-6 inches away. But im usig 125w bulbs, so dont know if its different with theese. But ur colling are looking good, might steal some ideas from that.
i painted everything flat white. around here mylar is only sold in bundles, the smallest being 45$ and i dont need that much so i just stuck with the whiite paintConsider lining the sides with reflective mylar, it will enhance lighting.