L's, to add to what has already been recommended, if overcrowding of BG is the reason you have small BG, adding additional CNBG (even if their genetics are superior) is only going to add to the overcrowding problem. If genetics is the problem (which as sprkplug has indicated from his pond experience that to be unlikely) then the CNBG might help.
Point is, need to know what the problem really is before trying to fix it. You might only be adding to the problem rather than curing it.
In my very limited experience and mostly based on what I have read here on PBF, your problem of small BG is much more likely a need to remove some fish because there are too many for the BOW, rather than poor genetics. But I'm as far from an expert as you can get so take that advice with a grain of salt.
Last edited by snrub; 12/29/15 08:16 AM.
