Potters are notoriously difficult to get eating, you'll even find 2 on here that lost recently. If you qt, putting a mature rock with micro algae on it for grazing helps. Resorting to live foods like black worms, brine shrimp, or pods also helps. They may even respond to clams on the half shell or masstick the food that you can smash into a rock for them to pick at. If they 1st don't take to the clam, put one in daily for a few days in row and they may eventually take to it. Other foods are hit or miss, brine shrimp and mysis is usually a couple of the 1st ones they eat.