what to feed a large cuc?

[spacenyc]

Always like a large cuc, one of my fav parts of reef tank. have a 34 gallon and high phosphates in the water so i assumed they would have lots to eat. let the tank get overrun with every type of problem algae before introduction and within four weeks almost all gone; first time having an urchin i think its a lot more efficent than i assumed. so two questions really what should i feed them generally and what can i feed from local markets , probably asian, that is easy and affordable