Usually, people here talk about how may pounds of LMB to remove per year. So the number of fish isn't as important as weight. In unfertilized ponds, the general statement is 10 lbs/year. for fertilized, typically they say 10 lbs/year. This could be much different depending on your specific situation.
I typically try to meet my quota with LMB < 14 inches. However, here is also a theory that in a LMB crowded pond where the LMB are stunted, you may be better off taking the larger ones because they'll never reach their potential but the smaller ones have a chance assuming some changes are made to have more/better forage, better water quality/etc.


1 ac pond LMB, BG, RES, CC