I got a great deal on a used 29 gal tank from Craigslist, went and picked it up yesterday, set it up with the cichlids and decor that came with it. Everything was fine, running smooth, and most of all quiet. I took all the cichlids to my LFS today because I an not set up to handle them (a whole 'nother stroy)...came home and proceded to change the tank over to house my glo-lites, dwarf rainbows, and rubber nose pleco. Cleaned all the aweful green gravel out, kept the filter running to help clear the water of all the junk. Added my new gravel, scaped, added said fishys, everthing went fine. I shut the filter off to add some media and when I turned it back on it started making the worst humming noise! It sounds like an ancient air pump rattling on a hard surface. Water is circulating fine but there is a slight 'leak' from the "intake side" comeing down from the filter around the intake tube. Can anyone help me calm this thing down. At this rate I will never be able to sleep tonight!