Personally, I put babies in a 6 qt tub until approx 300ish grams. I put them on paper towels or aspen with a black box hide. If not in a rack, I use a small UTH with thermometer and thermostat and black out all but one side. It only allows for only one hide at this size and a water bowl, but I've not had any issues with this set up. Plus this is relatively inexpensive until they are ready for a bigger enclosure. Some babies do fine in larger enclosures, but this is what I would do for troubled eaters, so I just do it for all of them now.