Stick to fish with shrimp. the biggest ones in my tank are neons.. (which i have only seen one take a nip at a shrimp once)
Unfortunately once the fish figure out how good shrimp taste, they will not stop eating them.
I had cherries with my rose line sharks and ember tetras for about 8 months before they figured out how a shrimp tastes. Guess what, 2 days later there were zero shrimp left. Haha.. About 500 or more cherries gone overnight after 8 months of peace.