The puffers will only eat live/frozen food. If you're trying to feed them flakes they won't touch it, try frozen bloodworms, frozen brine shrimp, frozen mysis shrimp as a varied diet (they like bloodworms best) and get them some small snails to eat, they will go crazy for them and they need the shells to grind down their beaks...What kind of puffers are they?
everytime i wake up. another fish dies. is it the puffers that are killing them?
Are the deceased fish chewed and ragged? or are they just dead? ...If their fins are chewed and ragged, then the puffers are probably the culprits. ...but if not then it could be a water problem.