So I'm getting 4 baby sulcatas I have a couple of 4 foot by 4 foot pens that are not being used should I put them in that or start out with something smaller?
If you can control the condition in those, then bigger is better. I start mine in four by four enclosures, but they are closed chambers and it is very easy to maintain the correct environmental parameters. In a normal heated house it will be very difficult to maintain good conditions in an open topped 4x4' table.
I have my red foots in 3 4x4s all 8 now I do have my top enclosed and it retains a humidity level of 90 or better that should be good to do with my sulcatas now having about 5 4x4s left to use should I do 2 in each 4x4 that's sounds like a better idea what do you think
I would not do two in each because more than likely one will bully the other. If you split them up, make it three in one and one in the other. I would combine the enclosures to make it larger or just keep the four in one until they get a little larger. That is just my opinion. Others will tell you what works well. Good luck and keep us updated. Pictures are always nice for when you get them!