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If the bass were taken from another body of water via angling, then they could still be there, but getting hook shy from getting caught a few times. If you are seeing 6"-7" bass, then the ones that you stocked pulled off a spawn last year (if you didn't stock any smaller bass).

If you want to grow the biggest bass possible in that BOW, then I'd try to limit the number of bass in there to 50 and not fish for the bigger ones at all for a few years. You will need to fish for the smaller ones, and start removing 20# of bass per year from the pond so they don't eat themselves out of house and home.

If you have underwater plants established, I would go ahead and add the crawfish and golden shiners.

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).