before you buy your flame ask them to feed it to see if its eating, if it spits the food out pass on it because its most likely stress, find out what they are feeding it and try to feed the samething
but feed a varied diet or your angel will not survive for a long time (past 4 months) I would feed my flame algea flakes, nori(seaweed), brine shrimp(enriched), mysis, ocean nutrition angel formula frozen