Algae clips that we use to feed our tangs and other herbivorous fish are a good way to present various types of sheet algae to our fish. Some fish will readily take food from these clips, while others shy away and favor picking on the rocks. If this happens, try a few things. First, use a variety of foods, both meaty and leafy, to coax the fish to eat. If this still doesn’t work, try to put some algae on the rocks and let the fish discover them while it grazes. You can use a rubber band to attach the food to the rocks or simply wedge it between something.