I've been maintaining a 500 gallon hot tub pond in my yard for about 9 years. Although I messed around with pumps and filters in the beginning, I found that it would sort itself out. Every few years I will drain it and let the rain fill it back up, but that's about the extent of my involvement. It doesn't stink, the water is clear, the lillies grow great, and mosquito minnows and goldfish grow in there indefinitely. I decided to install a 130 gallon stock tank pond using a raised container full of local native plants as filters, and it is as clear and clean as pond water gets. I'd say I've been lucky because I am not educated in the ways of the pond beyond the basics!
That said, I'm looking forward to learning more in order to understand what is actually happening!
That said, I'm looking forward to learning more in order to understand what is actually happening!