Pond Boss Forums GENERAL QUESTIONS Help Fish Kill/ Yellow Perch Survival/

If you are using the pond for closed loop heating and cooling, putting cold in during the Winter and heat during the Summer (presumably towards or at the bottom) from heat exchange through the coil, that will be doing some destratification by itself. Aeration may indeed be required to keep a good fish population - you may have to eat some resulting inefficiency in your HVAC as a consequence.

I personally doubt 6"-7" YP stocked in the Fall of 2024 pulled off a spawn last year. Males might have been big enough, but I doubt the females were. Dr. Perca (Bill Cody) can confirm or obliterate this opinion.