It should open up alot. They burn easy if under too much light. The tissue will start losing its color if this is happening. Does it open up at night? They tend to open up in the dark. As for feeding I feed mine monthly 2 to 3x mostly small peaces of cut up sclops because they are soft.
75 gallon (just moved every thing from a 55 except for the cc.I have a purple tang,blue damsel,pinkand blue spottod goby,bicolor blennie,3 percs,rose bubble ,green bubble,some gsp,zoos,and to colts along with the brain.Water checks out fine.I still have the canister from the 55 running until the wet-dry can handle the bioload by itself.also have about55 pnds figi rock and 10 tonga.Herse a tank pic