I'm glad to hear he's eating for you! About 5-7 days is the recommended here for a feeding schedule. A black light should be fine to use for night, my "moonlight" bulb looks just like a blacklight. As for leaving him, if you don't have a thermostat and timer hooked up to the light and UTH I wouldn't leave him, just my opinion. If you don't have anything or anybody monitoring the temps they could get too hot or too cold. That's just me.