range around 70-75 degrees tops. Colder and they won't sprout roots easily. Warmer and you get rot and mold. It's a delicate balance to be sure.
I agree, it sounds like it may be just about perfect but I would never get into that habbit just because electronics and water dont mix. I keep everything under my 400w MH indirectly and as they age they just get moved more direct, my light is on the right most side of the closet and the left side has my 15 gallon kitchen trash can I use as nute res and room in front of it for 2 trays, once seedlings pop or clones root I move the solo cups on top of pots already growing to the right and this way the seedlings and clones are the same height as the main canopy, I veg normally for only 3-4 weeks as I mostly clone and they are already mature 2-3 weeks after the initial growth starts after root. saving space is main reason I do it this way but mostly for the heat from the 400w, I am under the lamp and its fine, by using solo cups covered with plastic wrap its very easy to keep the light from directly hitting the foliage until rooted as the angle is enough to keep the inside lip in light to stay heated but not enough to where the light is more than halfway down inside the cups hitting foliage. I have never had any luck with the domes and heating pads unless just popping seeds, clones rot from too much humidity and cups covered in plastic I found was the perfect greenhouse I needed while not over watering from too much humidity building up in the dome
reapplied rooting gel to ones with none. Keeping the bottoms of the cube semi soaked (keeping them under HPS light to make the water evaporate and cause humidity.)