Not sure where you are located buta bag of frozen tilapia fillet is pretty cheap here.Also,a lot other types of fish are rather flaky and tends be a bit messy in the water.Ideally I'd like for him/her to start chowing down them xl market prawns. Almost all my other fish take them regularly. I should probably add some more selection to their diet though. Will try some fish filets, tilapia or whatever's somewhat affordable at the market.