How big is your Lionfish??? Mine was about 1.5" when I got him and he is still to small to attempt to ween him. Most silversides are too big, and the appropriate pellets are also too large. Usually though you take live with frozen feeder saltwater shrimp, slowly changing the ratio till only, then move on from there. Some people have luck with getting them to eat live foods for awhile, then letting him go hungry for awhile, say a week or more. Then they add a pellet or thawed silverside. Eventually he gets hungry enough.