WHAT DO U FEED MUSHROOMS

[Rikko]

Typically they get enough nutrition from the water column. You could target feed with a liquid invert food but I think that would be excessive.

Has anything changed? They usually give a good indication if something's up in the water. Did the temperature drift suddenly? Salinity? pH? Lighting? Did you move it?
Test everything you can and make sure nothing's gone funny.. Mushrooms will sulk sometimes but generally they should be pretty healthy.