My pl*co likes to eat spinach and romaine lettuce (don't give it iceburg lettuce, it is very low in nutrients). What I do is I take a piece of slate or other rock and attach the lettuce or spinach with a rubber band so it will sink to the bottom. My pl*co loves this, that is, when the goldfish don't eat it first. You could also blanch the vegetables to make them sink, but this does take some of the nutrients out and the fish seem to enjoy munching on the raw stuff. If yours won't eat it, try different vegetables or just let it continue to eat the wafers and algae. Once it is used to eating these foods, it can be tough to get it to change.