I found this type of filtration very interesting. I don't know how many of you are into the saltwater fish and reef hobby. One of the mainstay's of reef filtration is "live rock". This is really dead coral skeletons that have become extremely porous. It will harbor both aerobic and anaerobic bacteria for complete denitrification. This bacteria house media seems to work on a similar level. Has anyone tried "lava rock" to see if it had the same effect? It is possible to make an artificial "live rock". I have made about 50lbs of it and have been using in my reef tank for 2.5yrs. The web site to learn is
www.garf.org and it is called argocrete. I am curious if anyone has tried something like this as a filter media for ponds. I also wonder the effect this saltwater sand based media would have on ph and hardness?