I have a Pencil Urchin in my 32 Gallon biocube tank. I've attached a picture of it. It seems to have a good amount of algae in it. I have algae wafers that sink. I notice when I put it in, my pistol shrimp is quick to detect it, and take it into his burrow. I have concerns feeding my pencil urchin because I've noticed a few spikes laying on the sand. I've checked my water parameters (nitrate, nitrite, and ammonia), and they look healthy. Do I need to provide it with more supplements? Should I be putting dried seaweed like this, in there, for it as a supplement? https://www.liveaquaria.com/product/prod_display.cfm?c=3468+3762+4177&pcatid=4177 I am guessing it would be able to "detect" it, and draw near to it. Or should there be enough food in my tank as-is?