23 degrees Celsius is that on the hot side of the tank? Heat emitters are for night time heat not for basking light- you can add a CHE but you must use a solid clear bright white bulb for basking - it provides UVA CHE's do not --- other light? which light are you talking about? UVB's are not supposed to be real bright they provide UVB rays and do not emit much heat at all -- you want surface basking temps 95-100 F --