[Sirena Doren]

Well... It sounds like it is a mechanism problem if it doesn't work at all. If you're hearing sounds coming from it but you don't see any water intake or outflow then it could just be clogged and need to be cleaned with a carbon change. If you've only had the filter a month, it should still be under warranty and you could contact the company about getting it replaced. If you don't have another supply of oxygen for your fish, you're going to need get a temp. replacement until you get a new one from the company or get an oxygen stone. You should be good without filtration for a few days but you'll still need something to create dissolved oxygen. Oh and typically, if you bought it from PetsMart or Petco, if you've used it for a month and it didn't come broken out of the box, the store won't replace it. You will have to contact the manufacturer to get it replaced. They're the ones who create and uphold the warranties, not the store from which you bought it.