I have had 6 in my 125 for about 6 months. Started with 8, but 2 died w/in a week. Since then, they all school a good bit and my 2 clowns will sometimes school with them. The biggest one clears out his spot when it's time to eat, but other than that, they get along fairly well. They do like to eat more than once a day though and are more peaceful since I started feeding them more often.