Fair enough. Here are my goals. Hope this makes sense.
Of course, all this depends on what is possible with my setup....
I think of a pond as a, more or less, closed ecological system. I'd like to maximize the diversity of species in the system, and have wildlife balanced in such a way that is sustainable over time, assuming occasional tweaking from me.
I'd like to see healthy fish, frogs, snakes, plants, whatever could live there compatibly, in a good balance.
I can control the input of fish species and the numbers, the habitat for natural species to some extent, the health of the water, water plants. I have heard that the siphon drainage system provides better water turnover, and results in a healthier pond, than the old standpipe drain-from-the-surface
But it might be months before I could get the new drainage system in. Meanwhile I've got the summer free and I'd like to do what I can, now.
I've noticed as the water has gone down, it has provided swampy areas around the edges that seem to be more beneficial for the frogs. There are many more frogs than there were before the standpipe rusted. This should also help newly hatched fish species I would think. Sometimes I just call these minnows, probably incorrectly, covering all speces of stocked fish.
When the new drain system is put in place this will change. Maybe I can make this change more gradually. Not sure if that's possible with a siphon system, though. Probably not.