I’ve been installing ponds based on this technology for over twenty years. I’ll take a well designed natural plant filtration system over a mechanical bio filter any day. Don’t get me wrong, I use bead filters & such in certain applications, ie... ridiculously high fish loads, ponds without waterfalls, etc., but they cannot cover the ground that the “Veggie” filter can.
I created the system shown at the top of this article in a commercial application in Davidsonville Maryland years ago. It is part of an elaborate koi pond, stream, and multi level waterfall feature that we installed at no charge as an advertising display. The owner is a pond supply company. We originally installed bottom drains, a large bead filter, a UV-filter, 2 external pumps and one submersible pump. He was continuously dumping barley pellets into the pond and stream trying to control a constant algae problem (no luck).
Long story short, he left everything running throughout the winter, and cracked his UV, and bead filter. He didn’t replace them, even though he owns a retail supply store. (Not the best businessman). I told him I could take care of it another way.
We added the water hyacinths and Iris (river jack was already there), and watched the pond system transform in short order. The water became the clearest it had ever been, the ammonia levels- perfect, nitrate conversion was fantastic, the expensive show koi were as healthy as could be, and the algae disappeared.
Irony-The broken equipment is still there, doing nothing but looking useful, and is probably used to sell similar equipment.