It depends. If it is standard tetra min type inexpensive flake or similar, then no I wouldn't recommend it. There are foods that can be given to both though, like frozen Piscine brand mysis, daphnia, encapsulated brine shrimp eggs,Hikari bloodworms. Even some dry foods...I give my sw fish a little flake sometimes{along with frozen for the day} and give both them and my fw fish the same Ocean Nutrition Formula one, Hikari Algae tabs{my hermits go crazy like it's a treat} and other foods.