Tom :

I could not reccomend using GSF unless you are going to have bad water conditions. I think they have undesirible genetic traits for ponds. Small size and low fecundity ( # of offspring) for the amount of space (bio-mass/carrying capicity)they take up. Hybridizes with other lepomis ( BG,RE RBS etc) with poor long term results. Also pure GSF stock is often hard to find. In my opinion BG and RE are a better choice and grow just as well if water quality and forage are good. Here is some info below you can compare. Plenty more info around if you need more let us know. ewest

GSF link
http://www.cnr.vt.edu/efish/families/greensun.html

BG link
http://www.cnr.vt.edu/efish/families/bluegill.html

RE link
http://www.cnr.vt.edu/efish/families/redearsun.html

Fish Base- GSF
http://www.fishbase.org/Summary/SpeciesSummary.php?id=3371

Fisg Base--BG
http://www.fishbase.org/Summary/SpeciesSummary.php?genusname=Lepomis&speciesname=macrochirus

Fish Base -RE
http://www.fishbase.org/Summary/SpeciesSummary.php?genusname=Lepomis&speciesname=microlophus