Pumping the water from the main pond into the forage pond and letting it flow back into the main pond is the best route to take. Don't let it bounce on rocks or the fish will do the same.
In this hot weather, i.e. water temps in the 80°F+ range, any handling of fish other than letting them swim with the outflowing water will kill some, possibly as much as 50% or more depending on how careful you are with handling fish.
There is a reason why the fish hatcheries in Arkansas don't handle fish from late June thru Mid September - they lose too many due to handling stress.
Now, warm water fish, like Tilapia and Catfish are different, but you still have to keep O2 levels up and be mindful of any bud/silt getting into their gills.
If you are going to completely switch species for next year, drain the forage pond dry, and leave it that way for a few months. If water collects in it, even a footprint sized puddle, I would use hydrated lime liberally a few weeks before filling it up and restocking it with the new species.
Thanks, Dave, quarter acre, and Scott. Based on what I'm seeing here, I've decided the smartest thing is to pump in some water from main pond into FP and aerate in 2-4 weeks (waiting for electricity to be wired up for compressors, this is fast as possible). Drain when temps cool in mid to late September.
If they don't make it thru summer, well, the coons will eat hearty but it won't hurt my main BOW. CNBG are well adapted to heat so I figure they have a fighting chance. Might still net out some YOY to reduce bioload, but we'll see.
Re next year, I've heard it is wise to vary type of fish in FP due to possibility of disease. Don't know if that's true, but that's part of the reason I want to switch to TP. Also, TP apparently can be grown in greater quantities than CNBG.
