Hello! I have a bearded dragon that was rescued. Growing super fast, I want to move him to my 40 gallon tank, I have him in my 20 gallon right now with 75watt basking bulb.....Should I use a 100watt for my 40 gallon or do you thing the 75 watt is ok? Also he has been hiding for the past few days, does this indicate that he may be too hot?