lots of protein! i find that sinking pellets are the best. feed fewer of the pellets than the floating kind. the floaters are "hollow" where the sinkers are food all the way through.
i feed my sa (south american) and ca (central american) the following.
a.m. - pellets
noon - rotate between bloodworms, brine shrimp, chopped shrimp, and beefheart
evening - floating color enhancing pellets
i find that feeding the floating pellets at nite is easier as the fish are more than likely to not be all that hungry. the excess is scooped off the top. in the morning i vaccuum all of the substrate for excess food about 30 minutes after feeding. i do this by placing a nylon over the end of a short peice of syphon hose and letting the water flow back into the tank. the debris is caught in the stocking. also on occassion feed 100% beef hotdogs the kosher kind as a treat. any pellet food that is fed is soaked in tank water for about 10 minutes before feeding also.
hth
maggie