just about to go to bed as leaving the room i looked over at my 127 lt tank that has 2 kribs in and noticed no water movement from the filter switched it off then back on and heard it start up removed the head and the plenum is spinning checked the hoses no blockage . I had to rush up into the loft and get one of my old fluval 306 out and move media over and get it up and running . Dont know how long it has been like that the thing is it is just out of warranty don't think I will get another one I do have one on my 250 lt tank hope it holds out.