Please help I got my fx6 filter second hand with my tank and it was working fine for first 3 weeks then I noticed flow rate was really down, Iv Google’s it loads but can’t get any answers, Iv done the obvious things check for blockages clean out filter ( want very dirty at all) also cleaned impeller and got a new impeller. I did notice that after fitting new impeller it had possibley slightly more power but was running quietly again and now after a few days the filters rarther noises. If any 1 knows what it could be I’d be so happy, I’m fed up taking it apart now and getting no ware!! Thanks