i got a used tunze 9005. after disassembling and cleaning it inside-out, i placed in a bucket of water and ran it. but it is as noisy as my old seaclone (that's bad). even after i shut off the air, it is still noisy, but a little better. i think i may have re-assembled it incorrectly which may have caused it to rattle. how should the power cord and the air tube be run inside the box? and how is the pump seated? should the thin side or fat side of the powerhead point toward the front water intake? thanks