My tiger barbs love lettuce as well as shelled peas and cucumbers. I blanche them all with boiled water, and then allow them to cool before putting them in, but they seem to love it all. I dont think there is anything that you could put in there that those little pigs wont eat LOL . Mine also eat flake food, shrimp pellets, bloodworms,, basically everyting. The only problem i have with them, is trying to get them to share with the rest of the fish. LOL
Sandy