Hi, I new to reef keeping. I want to know what type of food do corals eat? I have 1 purple star polyps, 1 yellow polyps, and 1 button polyps(purple and yellow dot in the middle). My purple star polyps has been living for a months now and show no sign of dying and is doing great. I never fed it anything. Today, I went and bought two more corals and was thinking to myself, they have to eat something. The associate told me to buy some kent marine food for it, but I did not think it is necessary because my star polyps did fine without anything. Is it neccessary?? Could I overcrowd my 20 gallon tanks with coral like fish?? Like I said before, I am new to this hobbie and any advices will be greatly appreciate.