I'm fairly new to saltwater, but from what I've seen most fish don't eat the first day you put them in... But a day or even two later the look for food.. Whatever you put in there they will eat... But you should really find out what they eat first and feed them what they should be eating... I use a feeder station... It works great. The fish know where to go to get there food and they can already tell what time I usually get home... It's crazy how fast they learn.... Hope this helps... And I wouldn't put any fish in a 5 gallon tank for to long with out filtration.... You should use that for more of a acclimating tank... I use a 3gallons myself. Just set up a water drip and your set. It's really the best way form my personal experience.