RETFs: How many??

[Kurt]

I'm looking at the glass front opening Exo-Terra tanks, is the 24"x18"x24" good enough for 4??

PS - How do you sex RETFs and at what age is this possible?? I'm thinking about getting 4 juveniles instead of 4 full grown guys/gals

Yes, 24"x18"x24" is fine. Unless they sing or lay eggs its hard to tell gender. They can breed within a year.