Thanks for the size recommendations.
As to the tank precaution, I have had Bettas in my other Fluval Edge tanks all this time. There is an area at the top of the tank that is open to the surface and they've never had a problem.
I'll keep him on my short list!
Endangered Species tank: Colony of Charachodon encaustus officially registered with the C.A.R.E.S. Preservation Network.
12G Rimless Club