I am no expert on fish, but I would give your Potter's Angel some more time to adjust to your tank. I just got a Coral Beauty Angel about 3 months ago, and it took him 3 12 weeks to start eating live food. I feed him a little blood worm and live brine. When I first got him I was worried, but since all the CB did was pic at rock all day, I didn't spend to much time thinking about it. You also might want to try feeding your fish somegreens. I will say this, Potters Angel are one of the harder Angels to keep, so watch him carefully. Hope this helps.