hi question about mandarins

[loggix]

hi , had my tank up for almost a year have plenty of live rock
all along my glass i have pods little white bugs, i bought a mandarin
because i thought he would have enough food, he seems to be finding food hes pecking at the rocks alot but he still looks like his stomach is shrunk he has good color, ive tried to target feed him with live hatched brine shrimp, i still see lots of bugs crawling around, should i start a rubble pile in the back and put some mysis in that ,well if he doesnt fatten up soon im going to return him.but what confuses me is theres quite a bit
of pods around still or so itseems anyways any suggestions?