Thanks, it's been a interesting experiment.
For filtering, this late Fall and Winter we've just kept a long airstone, next to the Ebo-Jager, hooked to an airpump set at low flow and didn't feed the fish much. No filtering other than the Lilies and Water Hyacinthe slowly growing. Not much bioload with less than 70 little fish in the tank. Since the Koi tank, and settling pond are part of the whole set-up, (approx 500 gallons total)..
..later this month as the days' lengthen, the main pump will be cleaned and turned on, the settling tank cleaned and the plant tank will clear green water like it did last year. I was pulling pounds of Water Hyacinthe monthly from the plant-filter tank.
The settling pond will probably get some stem plants to assist. I'm thinking of getting Elgeria Densa.
We got a huge hatch-out of Daphnia in the settling tank last spring and it fed everyone. Not sure if the Daphnia will do so again this year. I'm hoping to get the Rosy Barbs to spawn this year, they've colored up so prettily, you'd hardly recognize them from the little silver runts they were last spring.
See that's the thing ponds and tanks that go green and all hair-algae aren't actually a bad thing. There's usually a lot of good food in tanks that go this route, Jorge Vierke is of the opinion that a green water or algae infested tank is a good place to put stressed and weak fish. It's kind of a fine line to run there though.