Thread: ideas for semi-aggressive fish in 40 gallon tank?

what kind of fish is colorful, interesting, middle to top swimmer, and can live with clown loaches, barbs, silver dollar and bala shark?

I had a setup almost exactly like that in a 75 once, minus the silver dollar. I added hatchetfish, which sit at the top of the tank most of the time. They're really neat, especially if you can find some marbled hatchetfish. They have them on liveaquaria.com, but you don't wanna spend $35 after shipping for a few $2 fish. They're not very big, and they like to be in groups, so get a bunch of them.