posted 10 years ago
I've been thinking about using biochar for the medium in my media beds. Seems to me that it might be good as it has such a high surface area (I think hydroton and expanded shale do also, the usual media of choice) so it would have lots of habitat for the nitrosofiers and nitrifiers in the system, and so make a really good biofilter. I think, since pathogens tend to be anaerobes, that as long as you're careful with your DO levels, and make sure your system doesn't have any dead zones, that there isn't any reason why it should be a problem. As far as I know, biochar is pH neutral, which is one of the main things to worry about.
If nobody knows for sure, maybe we should try it and see how it works.