What do you want from the
pond?
Growing food? To thrive without inputs?
In either case doing the least amount possible. Add some rocks for crevices on the bottom. Minimal fish and dont
feed them. Whatever leaves fall in, let them stay. It will balance itself out.
That basically describes my
cattle troughs. Minnows eat mosquito larvae and breed in the rocks. No feeding means no big algae blooms from over feeding.
That water can feed plants a
bucket at a time. Once you move into aquaponics you are adding inputs like pumps, adding more fish than can sustain themselves, etc. I'm not sure what your final goal is.
Permaculture + ecosystem doesnt equal pumps , aerators, and fish food. Clarification of what you want would be good.