I have heard of flame angels being finicky eaters, but rearly. Umm, I would try a mixture of mysis shrimp, maybe some live brine, frozen brine mizture, formula one or two (they eat veggies?) I would start out with a form of shrimp to get him eating though. Later on hes gonna need some psonge in his diet I bleieve. Hopefully ur tank will develop qtip songes. If not, there is an angel formula for wen they are mature. Well, good luck, sorry bout the loss.