If you can make a shallow wetland and have the water flow through that, the plants will remove a lot of the nutrients. People that make natural swimming pools have a wetland the same size as the pool remove the nutrients, and the water quality in the swimming pools is like the water quality in the swimming pools that use chlorine and filters. The downside to that is the area needed for the wetland and how to move water through it, but with using the air lifts like you describe that should work well.
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