Filtration media placement

[Bordeben]

Can you place the filtration media you are using for the growth of bacteria in an nft system at the bottom of the pond and just draw the water from a lower point than the media rather than putting the media in a separate filter?

[cgindiana]

That sounds a lot like an under gravel bio filter in the aquarium world... While they work with tropical fish ok with periodic gravel "vacuuming" I don't think I'd want to mess with a system like that with goldfish or tilapia just based on The excess excrement fish being fed to grow create. I'm still baffled by how much poo my system creates but my compost pile loves it!!