Tankspace for GBR

A couple of years ago a bought two GBR from the LFS, they lasted about 6 months before dying. I'm thinking I want to try again with some higher quality stock. Most of the info I have seen online suggests 10gallons per fish with plenty of hidding spots so they wont get too aggressive, but then i see pics like the one below on aquabid and i wonder if I have a big enough group is aggression less of a problem? I have a 20gal and a 40b available and I'm trying to decide which to put them in and how many to get. I may try to get a breeding pair and put them in the 20g or maybe get more and put them in the 40b. Thoughts?

Attachment 113546

I've had luck with GBR's although they are very fragile, they enjoy almost as pristine water as discus in my experience, and lots of hiding places with plants and wood. What size is your tank?

I have a 20gal and a 40b available and I'm trying to decide which to put them in and how many to get. I may try to get a breeding pair and put them in the 20g or maybe get more and put them in the 40b.

I breed them in groups. Abt 5m/5f in a 40b. Pristine water, 82f, quality food and some coverage. Aggression will be minimal if you give them enough territory. Which is abt 30cm diameter once they pair & pick spot.
Good luck! Either size will work for you, but i love the footprint of the 40b. They like the depth.
http://i1341.photobucket.com/albums/...psbdu7ivlt.jpg