That's a good explanation! I have to add beneficial bacteria to the filter to keep it in good working order.
I built a small wooden porch over the tile one to hide the 2 inch diameter pipes.
The main part is a 100 gal rubbermaid container filled with what looks like scotch brite pcs. and green rubber webbing.
Water hyacinth is an excellent plant to help filter the water.
water stays clear and the fish are a happy lot!
I got everything I needed from a local pond supply place except the rubbermaid container which came from my favorite store on the planet....Tractor Supply!
RobertB