You can do both -- I moved my 3 month old into a 4x2x2 Zen and the first couple of weeks he only used or went to the middle of the tank -- he mainly sat under the basking light or the UVB --- the UVB is center of tank in the front -- so he had the back part middle he would go but the far cool side he didnt go -- the UVB is out of the basking temps so he would sit under his UVB alot and basking log- he has two hides the one on the cool side and a rock one now under the UVB - he has not used the rock one yet but uses the hide/ platform a lot -- mine is now 11 months old -- if you want I can post a pic of the tank
Karrie