look at something like this

http://www.petsolutions.com/Seaclone-15 ... 3+C43.aspx

a second filter won't hurt you at all...............but there really is no replacement for a skimmer bud................... the next option would be a complete tear down, have the tank drilled and set up a sump and then you culd put a skimmer in it ..........but that a major undetaking i know

Boss