need schooling fish advice

Question
I have a 270 gallon tank that i got as a gift from my girlfriend. It has 6 jewel fish, 3 bala sharks, 1 parrot fish, and 1 angel fish. I need something to fill the void at the top. I was thinking a schooling fish. But something that the jewel fish wont attack and eat. Any ideas? i was thinking black skirt tetras, but i wanted a tighter schooling fish.

Answer
The best thing you could try is tiger barbs, they are semi aggressive and might be able to hold their own against the others, Though I can't be very very sure as all fish have their own personalities. But they school together nearly all the time and should have a group of at least 5. I hope this helps!