So this is my second eheim filter... I had a 2213 10 years ago but I sold it when I left the hobby.. and now I have a 2215 to go with my 55g tank.. anyways i don't remember them this loud.. 3 days old.. and it has a Hum like a fridge compressor running..? I took it apart.. and notice I can move the impeller left and right (or any direction) is this normal? I can't remember... Thinking of taking it back for warranty work.