It depends on what other lights you are providing besides the 48" flourescent. Is it going to be a UVB flourescent? If it is, it needs to be much closer than 3' to be effective. I believe if I'm not mistaken, that the flourescent bulbs are only good at about 12"? (this just came from reading other posts and care sheets). With a high ceiling like that, you'd have to either mount fixtures lower, or raise the area in the cage closer. My cage is 2' high, and I use a 120 watt halogen flood and a 160 watt UVA/UVB bulb from Big Apple herps and my basking spot is about 5"-6" off the bottom of the cage which puts the temps about 120-125 degrees. (I used the Powersun bulbs, but they would always go out after about 6 months of use, so it was time for a change. I just got tired of having to always ship back bulbs that were supposed to last for 2 years)
>>Does anyone have any advice on providing lighting for tegus? I am building an enclosure for our new Arg. Red and would like to know which lighting offers the most benefit - and how close (low) do the lights need to be in order for them to be effective. My enclosure is 7.5 feet wide by 3 feet high and I am thinking of a double 48 inch flourescent fixture attached at the ceiling. Any comments or suggestions? Thanks. map