I think you should find out if they're true perculas or ocellaris clowns or false percs, the true percs are not as hardy and are not for beginners they need a tank that has matured, the ocellaris are much more hardy and are a good beginner fish both are omnivores so they need their meat & veggies, brine is fine to get them to start to eat but they don't contain enough nutrition so you should go with formula 1 or 2 or emerald entree like people have suggested. I would also recommend that you wait awhile before you add anymore fish. Be patient and you should be fine JMHO
