Yup...my AC 70 took a dump..i had it on my 55g..the motor keeps making this loud errrr noise, so i cleaned it out, checked if the propeller was hitting the plastic...NOPE nothing i could find and also the propeller is somewhat hard to turn.......now I have no filter for the 55g and I dont get paid until friday....so now i must buy a filter and Im not getting another AC70....what filter should i invest my money into?