We are very impressed with our tetras and corydoras so far. Most of the corys and tetras come in pretty small sizes, so it is easy to come up with a nice combination. The rasboras look neat too. We decided to add a Male Betta in with our community fish and it is working out well so far. It is nice to see a bunch of schooling fish with different behaviors. I think the corys are especially fun to watch ( sand is a good idea if you go with corys ). We are going to try otos too, but haven't gotten that far yet.