Cecil is trying to be funny. Round cages are okay, many think better than boxes. Cage raising fish is not as easy as it sounds. One can kill a lot of fish learning how to cage raise a few fish. See below for past PBoss discussions about fish in cages.
Restarting a fishery in 9-10 acres is a big task you do not want to do. Lots of work and cost involved. Your current fishery is more complex due to crappie and a several bigger bass (2-5lb) with too few forage fish which is why you said "Not near as many HBG or GSF or Reg.BG as used to catch."
Achieving a balance in it as it exists will be a definite challenge. Catching grass carp sounds much easier than it is. If you had 20% coverage of naiad then about 20% is shallow likely less than 5ft deep. IMO it will be difficult to add enough structure in 10 ac to make it useful as fish refuge to protect small fish. Most all of it will become fish attractors and ambush points for the bass. Without weeds where are the nursery-refuge areas for small BG? Ideally it takes 20-30% of the pond to be effective. Develop an adequate feeding program to help compensate.
Fish In Cages - various discussion links.
http://forums.pondboss.com/ubbthreads.php?ubb=showgallery&Number=328176http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=304501http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=129073http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=104020http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=11750http://www.bassresource.com/fish_biology/rearing-bass.htmlhttp://www.tractorbynet.com/forums/rural-living/116055-fish-cage-ideas.htmlhttp://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=219337Other good reading material is three articles by Bill Cody in PBoss Magazine Back Issues:
http://www.pondboss.com/store.asp?c=9Caged Fish on a Small Scale � Part I. Pond Boss 15(5): 40-42. 2007 (Mar-Apr).
Caged Fish on a Small Scale � Part Deux. Pond Boss 15(6): 40-42. 2007 (May-Jun).
Caged Fish on a Small Scale � Part III. Pond Boss 16(1): 38-40 (Jul-Aug).
