Best way to run 4 lifeguard Fluidized Bed Filters???

[Hustler]

I have 4 Rainbow Lifeguard Fluidized Bed Filters I would like to daisy chain and run on the back of my 300g as a back up.
Anyone have any experience with them? and ideas the best way to run them/pumps ect?
I know they can back up if not dialed in right so Im leary....

[Hustler]

Also they are the 900 series...
Or if i can run carbon/GFO or bio pellets in them instead???

[Hustler]

Also if possible I would like to run them Inline from the sump and return to sump.
Someone has to be running them :)

[Hustler]

After playing with them and a measuring tape for a while I figure Ill run the pump out of my sump inline to the bottom of the first, then manifold it across the top and exit the top of the last back into the sump..... Seems to be the least resistance anyways.... If i can make them work with bio pellets, carbon and GFO great as Im still leary of the sand bed as a nitrate factory?
Any ideas or opinions would be greatly appreciated :)
They are big mothers lol
http://img.photobucket.com/albums/v601/dragonfish1ca/002-8.jpg