I am running something similar and think it is a worthwhile mod. You can take a MJ1200 that normally pushes 295 gph
and get somewhere in the neighborhood of 1400+ gph
Most of the mods use pvc
and a RC boat propeller(s). There is a LONG thread on RC about this. I am running one from a guy that was molding propellers as a kit and but can't recommend him since he is no longer answering e-mails. The DIY route is easy enough but I chose not to fool with it this time. Mine works great except I have mine on a wave timer. Since a maxijet can reverse the direction of the impeller, you have to have a stop on the kit to prevent the impeller from sucking instead of pushing. Mine gets stuck and won't correct itself. Definately moves some water. Pushes A LOT more than my Seio 620.
*180 gal Display, 100 gal basement sump, 33 gal refugium, 3x250 MH, 2x160 VHO actinics, zoos, some softies, LPS & lots of acros and other SPS.
*100 gal prop tank plumbed into main system w/ 2x96 PC lights and 1x150 MH,