I've fed it twice (1/4" piece of raw shrimp) since I've had it. Once in each of its first two locations. My plan was to let it pick up the mysis shrimp from the water column when I feed the other fish on a daily basis, and to feed the raw shrimp 2-3 times weekly.
Since it's moved into the area behind the rock, the tentacles are extended, but I haven't fed it again. Was thinking i'd give it another day or two, and hopefully reward it for moving to a new location.
For what it's worth, there's a pic of the anemone just after I got it at the
end of my tank photo album page.