Hey,
I'll start this by saying I'm no expert. That said, I believe the wider variety of foods you offer the better off your fish will be. I like Formula One and Seaweed Selects. I also use Brine Plus. Don't feed just brine shrimp because although your fish love it and wipe it out, it doesn't have much nutritional value. I also don't personally believe in using flake foods in a SWF tank. A good idea is to check with the folks you get the fish from and ask what they've been eating. (It's always a good idea to see your fish eat before you buy them.) HTH
Dan'l