Hi, I`ve noticed recently that the flow from my Fluval 404 spray bar has significantly reduced. Even after cleaning it and checking the function of the impeller (which spins fine) I`d say the flow has roughly halved. The only other thing I can think is that the 2 pipes may have a restriction?? Would this be a possibility, because after all they just carry the water back and to, so how would they `block`? Any ideas, thanks 







