I have 65 gal
tank ... currently only have 4 fish .. two semi aggressive chilids and a pleco and a catfish. I have a canister filter system ... at first it worked fine and was silent .. but I moved several times and this last time I can not get it to be quiet again. It makes a loud cavitation noise .. then is quiet a for a few seconds and the does it again. I have taken it apart cleaned it and put it back together twice and still cannot find out what makes it make this sound. Anyone have any suggestions?