Well number one it does depends on the colubrid, not all colubrids have the same heat requirements, Hognose Snakes for example need a higher hot spot than Kings or Milk etc, you need to know what the requirements of your animals are.
I currently do but I have also kept colubrids with no hot spot, in that case the ambient temps is higher than the one provided when offering a hot spot.Who uses UTHs for their colubrids?
Does anyone use supplemental lighting along with the UTH?Ambient temps is about 74 and hot spot about 84 (those are for Bulls, Honduran Milks, Texas Rat Snakes, Cali and Brooks Kings)How are your ambient and cool side temps?
I would provide adequate ambient temps with a oil filled heater or additional UTH and thermostat depending on the size of the collection.If your room isn't warm enough to keep ambient/cool side warm enough, how do you do so?