A 40 is fine, any tank mates will be nippes at overnight. Just in case you might put another growout in there. Expect some shyness too. My male is about 3 years old and still under 5".
Sent from my SGH-T959V using MonsterAquariaNetwork App
I put 5 one inch grammode juvies in a 75 gal in July 2010 with some dithers, and lots of hiding places, by that Oct, there was just a pair of grammodes left. The remaining pair did spawn in the 75 over the next year, but the male killed his mate soon after the 3rd spawn.