There was an older post where someone (GUILLO1) was using a ViaAqua 2600 with a Sedra 5000 pin wheel impeller. There was something in there about scraping out some plastic from the impeller chamber to make the needlewheel spin freely. Not sure where all of that finally turned out though, because I think they were still having problems...
I think they finally mesh modded one of the impellers, link is a page around here:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1335995&perpage=25&pagenumber=7
I think they finally mesh modded one of the impellers, link is a page around here:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1335995&perpage=25&pagenumber=7