Question about Serpent Star

[cd5]

I have a serpent star in my 20 gallon SW, I feed him dry krill, how often should I feed him, the reason I ask is because I normally only feed him once a week up to once every 2 weeks, the other day my dad through a piece of krill in the tank and it floated, my serpent star crawled up my live rock got to the top and stretch a leg out and caught the krill as it was circling the tank and pull it down to him, then took it back down to the bottom of live rock where he normally is, does this mean I am not feeding him enough

 

[Fluff]

I feed mine at least four times a week. They love to eat. I would offer food more than once a week. Of course, he's no doubt scavaging fish food as well but, I'm sure he'll appreciate more.