I use a chunk of PVC on a string to feed nori to my fish. If I leave it in the tank and then spend any time viewing the tank when the PVC is empty, the fish flock to it like its feeding time and will spend quite a few minutes crusing past to check to see whether I have put any more on it. I really do think they could spend all day just eating nori. Hence I have started removing the PVC after they're finished eating it
