Problem with the UTH is the fact that up here in Bellemont, AZ temps at night drop to below 20 degrees. The only way I have been able to keep the temp is with the ceramic heater. The BP is in a 60 gallon that has been split in two using plexiglass. The BP gets 35 gallons and the Rosy Boa gets 25. I also am using a crushed walnut substrate but am thinking about switching to the reptibark from zoo med. Would this help my problem in conjunction with covering some of the screen top?