Hi Aimee. Are you doing complete daily waterchanges in the plastic bowl? Do you have a chilly bin (Esky in Oz, not sure what you call them) that you could place an ice pack in and then the plastic container to maybe bring the temp down. Maybe that might help. Also is the water high enuf to cover his top fin but low enuf to allow his feet to touch the bottom? And also, have you tried feeding your axie worms?