My acan is my most durable coral, hes in I'd say lowish light, bottom corner of my tank but in pretty moderate flow and has been loving it. Gets all the nutrients it gets from being the main point of contact from my gyre. With that said I think that would be best, put him in lowish light in med flow and try to spot feed. See if it can take any small meaty foods like mysis soaked in reef chili or reef roids. I also know mine loves reef energy from red sea, amino acids combo. That may help yours give it strength to fight out of perishing. Either way God luck hope he comes back. I've been nursing a hammer for about 2 months now finally getting it to make progress... again.. lol