i need help my fahaka puffer wont eat his srimp or krill, it's been 2 days since he ate and hes getting very skinny like his stomach is sucking in like a anorexic model. Also i've done a 50% water change added 2 table spoon of aquarium salt and i've added metronidazle for possible internal parasites. All his shrimp and krill are frozen. ty to whoever helps