You want distance for the T 5 12-15 inches- the long tube bulbs do not give off heat so to speak- you can use a regular house hold bulb no coil like a 40-60 watt depending on the temp your trying to get - what is the humidity in the tank? Optimal is 40-50% - are your using a dial hygrometer?Thank you for the input. It's a 60inch tank. With two 24 inch T8 bulbs.
They're due an upgrade in two months. At that time I'll switch him to one t5 bulbs over his basking rock (from the roof about 20ish inches from rock) and give him d3 once a week.
I wonder if I could put a regular non uv bulb in the other light fixture two help with heat/humidity