I guess I am lucky, this fish has proven to be super tough and hardy, and I can only guess it's the varied diet. I also have a Moorish Idol that eats all of these things as well an it has also proven to be very hardy. I have been purchasing the red sponge from LFS and placing it in the tank. Both of these fish will devour a fist sized piece in about 3 months. Not sure what nutrients are in it, but I attibute the sponge to some of my success.