OK.. Complete diet breakdown is:
1. Hikari food sticks (gonna get the bigger version once my packet runs out)
2. Prawns (1-2x a week)
3. FD silkworm pupae
Problem is, recently I weaned him off prawns (which he used to get everyday) and got him onto pellets which was really good. BUT he started to get really aggro at his tank mates (ate 2 convicts and killed 1 for fun), even though he has NEVER shown any interest in them. So I increased his prawns to every other day, and now he's stopped eating the pellets. :facepalm: He's now being starved so that he will eat his pellets again.
I don't mind stuffing pellets into prawns, but it's so tedious that I do it in big batches (1kg of prawns) and freeze them. Problem is, they get frozen together and I have to constantly defrost/ refreeze the prawns which I've read isn't good for it. Bottom line, it's just easier to give him pellets straight up. Once he's back on the pellets I was thinking of getting some locusts as a reward for eating the pellets, maybe 2-3 nights/ week (as per your advice).
Not having much luck with the silkworm pupae because whenever he bites it, it seems like 80% comes out of his gills, which I don't really mind because there are bottom feeders, but it's not going into him lol. Last night I tried soaking a massivore for a while to soften it but he wouldn't have it lol, so I think food sticks will have to do.