sebae feeding?

so i have recently gotten a sebae, now, how much or how often rather should i feed him? his foot is about 5-6 inches around and he is big, bigger than a dinner plate and hes not even spread out! i fed him a hunk of mysis the size of his mouth this morning, should i feed him again, twice a day or just once? and does the liquid phytoplankton help them at all and how often to add that? its in my 55gal

 

Sebae anemones are not as forgiving as say flower or Pacific Long-Tentacle anemones, so keep this in mind! Sebae's require very intense, preferrably metal halide, lighting for their success and survival. Feeding of these is not crucial as offering it shrimp, fish or clam once or twice a WEEK is all that they require. They get most of their nutrients from the intense lighting and water!
Feeding too much will just advance the negative high nutrient level often associated with the keeping of anemones. They also require excellent water parameters!

 

what lighting do you have?
and how big is your tank with dimensions?
what are your water parameters?
you dont need to feed it twice a day, maybe once or twice a week.