If he's doing it on his own, not forced, then I would say your habitat isn't warm enough for him. Have you measured the temperatures at ground level all over the habitat?
As much as he needs to regulate his body temp. This will depend on many variables including your ambient house temps. Try warming up the ambient in the enclosure and see if he basks less.
If he's doing it on his own, not forced, then I would say your habitat isn't warm enough for him. Have you measured the temperatures at ground level all over the habitat?
For any species general temps are suggested, but because every enclosure and household is a little different, fine tuning must occur. One of the ways we know in which direction to fine tune is by watching the tortoises behavior. If they never bask and always avoid the light and hang out on the cool side, things might be too warm or too bright for that individual. Conversely, if they hang out all day long near or directly under the bulb, it is a good indicator that things are not warm enough. This is a delicate balancing act and everyone must work out what is best for them.
The problem with sitting under man made bulbs for hours at a time is that they are very desiccating and they tend to dry out the carapace which can contribute to pyramiding. Man made bulbs do not heat evenly like the sun and even when outside, our tortoises usually use cover and take advantage of dappled shade and sunshine.
Keep coming back with more questions until you get this sorted. We are happy to help.
Thanks everyone. I've increased the basking temp by 5F and the cool side to about 75-76F. I've been observing my greek for the last 2-3 days. My guy likes to bask under the mvb for about 4 hours now. I don't think I should try to make it any warmer.