That thread was getting long so I started over. I keep 6 San Diegos in a Vision cage that is 3'x3'. two are males, they only fight during breeding season and I like that cause it almost guarantees eggs! I almost never see any of the animals because just like in the wild, they are under stuff all the time. They come out to eat wax worms from my hand. I would say a pair of any sex can be tried in a 20 gal. Just watch for problems and change accordingly. I used to keep 5 kingii (az) in a 30gal. My 2 texas have the run of a large vision cage also, but I think I could add a couple more with no problems.
Chuck
