Here some Q&A by Manky about the Anoxic filtration system.
Extreme plant growth is not uncommon in the Anoxic Filter.
Now I am probably going to get told off for this idea but fortune favors the brave and all that.
I have had a nightmare digging my new pond I am in proper clay and it all below ground 1.8 m. It has filled with water on me collapsed twice and been the most horrible hole in the world, but now its got a base and concrete block walls and its full of water again.
So here is my mad theory
The concrete block walls are porous and the clay behind holds water all year if I don't pump it out. So would I get the Anoxic filter effect from the thickness of the blocks with the clay behind? The way I see it a natural pond uses the Anoxic effect to stay healthy and this only works because it is clay. We waterproof our ponds thus isolating the water from the soils and clays that would give the Anoxic filtration. We don't want natural ponds as they collapse and form shallow dish shapes great for herons.
So do I leave it bare block and free to do its own thing ? What could possibly go wrong...........................
Anoxic filtration was designed over more than 25 years by Dr. Kevin Novak Ph.D. and it relies on the interaction of charged sites within the baskets, the charges on molecules and the kinds of bacteria that can live in an oxygen depleted environment. It's easy to do if you do it properly but doomed to total failure if you don't. Read how anoxic filtration actually works and how to build something that really works then decide whether or not you want to go down the anoxic route and the benefits it brings.