Welcome to PB posting.

You will have to manage the pond as the balance mechanism. Feeding will be critical for your goal. YP are known to stunt in the absence of predators (you being the main one). I would stock a few RES early (use adult fish). I would not overstock the GS but lean toward FH while the YP are small. You will need a predator that primarily eats 2–4-inch YP. A few WE might be the right one as you can control #s and size. Same for HSB but they may be able to spawn in your pond given the description of moving water and rock.

See this about HSB spawning in ponds.

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=26336&Number=336804#Post336804

Last edited by ewest; 01/09/23 12:17 PM.