you asked how many can you house in a 60gal. w/out aggression? i would say you could probably put 10 to 12 in a 60gal easily, maybe a few more. w/out aggression tho? i dont know. these fish can be real nippy with each other, the males moreso than the females. i would add about 4 or 5 at a time and offer them lots of hiding spots and places to play. if you happen to see one that is real mean, take him out or back to the lfs. good luck.
I got 5 more today, for a total of 6. They happily swarm around the tank together and eat together. I think I could easily fit 30 of them if I added more driftwood and plants.
