I have no idea. But, I ran across this place when researching filtration systems last year. I have not done business with them, nor any affiliation, but maybe give them a shout and let us know what they say. It looks like they have some pretty large systems.
http://www.emperoraquatics.com/complete-filter-systems-layout.php They're located in Pa.


www.hoosierpondpros.com


http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).