I'm with you and QA on this one Steve_. It won't be a problem for QA. Flatheads have never been observed to eliminate prey where they are forced to grow up in water. No water supports that. FH growth and consumption would slow as prey became scarcer. On the other hand, if a FH was put in a pond which was already supporting its limit of predators and the FH was big enough ... a lot of problems of prey shortage would result.

But QA's situation is different. His CC will begin eating mostly fish when they fnally get to be 24" or so. They will want 5" BG and there is risk that a large population of 4-5" BG will develop. If it happens, his plan is a very good one. His pond is small enough that a single adult coming in at 4 to 5 lbs would still be enough FH biomass to make a difference. So a 5 lb FH would put the FH biomass at 20 lbs/acre which is the lower end of the range most waters support (20 to 98 lbs/acre). If there is sufficient forage, after reaching 5 lbs, a FH could grow 4 to 5 lbs annually. In its first year, growing at this max rate, the FH would grow from 5 to 10 lbs and eat around 75 lbs of BG. There are 11 fish to the pound when BG are 5" long so the FH in its first year has the ability to remove around 800 5" BG if it were to grow at maximum known rates. A couple of LMB need to eat a similar number of BG. A FH is a voracious predator ... but it isn't going to upend the pond in a year or even 3. Some time ago, I posted a link to paper where in Wisconsin FH were used to transform stunted bluegill lakes into lakes with large BG. It did not happen overnight. It took 3 years to see notable improvement and then they made the mistake of harvesting FH out of one of the lakes which actually set BG growth back for a while.

Like you said, if he didn't want it in there, its easy enough to catch it out. This is one advantage of a small pond. Gehajakes pond is to big for a single FH to make a similar proportional contribution. Multiple FH and one could have reproduction that works contrary to his goals. No juice worth squeezing for Gehajake, I agree he is right in saying there is no reason for them in his pond.

But for QA, It could help a stunted BG population if one happens to develop. I've attached a grid of FH growth in a number of OK lakes. It usually takes 5 years to get a FH to 5 lbs (22"). How fast they grow depends on the water they are in and population dynamics. I have personally fished 3 of the lakes and these also supported LMB and Crappie populations. The reference can be found HERE.
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