Not really the fish stores problem honestly.... as someone who have went thru many regals, it’s very weird. Some are then stop, some never ate, some ate and spit it back out. All in all, getting them to eat is the hardest unless it’s a proven established one in aquariumThought I'd give an update. I kept the regal in the quarantine tank for a couple more days and monitored closely. The fin rot was slowly getting better but the fish would not eat anything- I must've tried a dozen different types of food and feeding methods. It showed no interest whatsoever. At that point, my gut was telling me it needed rocks and sand to graze on algae and pods and whatnot. I didn't feel good putting live rock and sand in the quarantine tank, so I took the risk and moved the regal to the display tank about 48 hours ago.
Hes been hiding in the rocks, but seems to be getting less and less scared by the hour. I've seen him pick at a couple of spots on the rocks and sand, but he's still not interested in commercial food. The fin rot is getting better and the two or three white spots that he had before are gone. I have noticed some white cotton-likengrowth in the gill openings under his mouth. I think it was there before but I couldn't see if because I keep my quarantine tank on the floor and couldn't get a view from underneath. It's very difficult to get a photo but it looks alskot like dead tissue and/or fungus.
I'm going to keep an eye on him and make sure it doesn't get worse. I'm considering treating with pimafix & melafix at half dosage rate for the fungus/infection as I've done that before in the display tank with no ill effects to the other fish, inverts or corals. It has worked well for me in the past.
Anyway, I feel like I made the right call by moving him to the main tank. At least he has the opportunity to graze and is getting the benefits of the larger water volume and stable water parameters. If I had suspected ich or velvet, I wouldn't have done it. And if his condition starts to deteriorate, I can always get him out and put him back in the quarantine tank. Thanks everyone for the input. Crossing my fingers that this guy can survive. Never buying from Pete's again.