I bought a large number of small koi several years ago for an aquaponics test, and they grew.
I'm one of those heretical pond keepers who encourages a diverse group of algae in some of my ponds. I've been raising fish for twenty years or so--saltwater, brackish, and fresh--and I have a little different take on what makes fish healthy and happy than some, though I was trained in the "right" way to do it. I do have pristine aquaculture systems, primarily for fry and food fish, but even those have a bit more of a holistic approach than some people take. As far as I'm concerned, whatever works and makes you happy is success and brightens the world a bit. I'm keenly aware that every climate and environment has different needs anyway.
Once the filter cycles again in this pond I'll clean out debris that's accumulated during the winter and do a small water change. The water will then clear up and look pretty good until the strong sunlight and increased appetites of the fish prompt a series of harmless algae (not cyanobacteria) blooms in the height of summer. Then, as the sunlight tapers off, the water will look good again until the cold takes over and I shut down the filter for the winter. If I ever manage to get enough plants growing in here that the fish don't just rip apart, they'll put an end to the algae blooms entirely, as in my other ponds. I've got rafts and partially submerged pots that grow plants in here that the fish can't get at, and we've talked about a secondary pond for plants and smaller fish with a spillway or small stream to this one. It'll depend on how much time we scrape together to work on it this year.
