They can grow just not like bass in a new pond would. My pond was full of 10-12" bass and after 4 years of very intense culling and adding forage now i have a bunch of bass in the 15" range. Some fish that were tagged back in 2009 have only grown a couple of inches while others tagged the same year are 18" now. If i could do it over again i would have just drained it and started over.