Love my little filter but it vibrate on the side of the tank and it's driving me insane! Any ideas on how to solve this? I've tried putting a piece of felt inbetween the glass and the filter, but it didn't really do anything. Tried taking off the lid, but it for a fact is vibrating the tank...

I moved my betta to a 5 gallon tank yesterday (formerly in a 3 gallon) and he's pretty happy. My whisper filter is extremely quiet, but today I put my ear up to the tank and the filter makes small, but kind of loud vibrations! My betta seems to be fine and never has any problems, but I was...