Just want to know how these work. I just bought a Top Fin undergravel filter and put it together and figured out theres not power cord to some kind of motor like thing that sucks up the water and spits it out somewhere. So can anyone explain to me how they work? Do I need to buy some other thing to make it work or does it work by just sitting there? Thanks!
Sorry if this has been posted somewhere else already.
Sorry if this has been posted somewhere else already.