[PapaBear]

Running a return channel to a post-bakki sediment drum would be interesting just to see if fines would flock and reconstitute to a certain degree.
In any case, your experiment and sound methodology have certainly made this a wonderfully educational thread (in spite of a few stray lightning bolts many pages ago).
Another question for you. Since I assume you still have plants growing in your now isolated hydroponics chambers, have you performed any tests on that water to measure changes there as well? I remember it being mentioned that there was some curiosity about the plants being a potential contributor of nitrate as well as a consumer. Just curious.

Quote: Originally Posted by dtbh Good question, Papabear. If you look at my pre-experiment set-up I have an in-ground filter that is being fed purely by mid-water. I have used this filter to assess the amount of sedimentation AFTER water is being fed thro' the BS/BH. I must agree that the mid-water feed to this filter is an admixture of unfiltered water as well as post-BS/BH filtration. I would expect that over time sludge accumulation would decrease if BS/BH performs as reported by some. Not in my pond. The sludge accumulation in this filter is way too much to be ignored. Perhaps those who reported that BS/BH gets rid of mulm may see some sedimentation if they run the post-filtered water thro' a long channel. My bet is they will see significant sedimentation. Anyone care to try? Cheers.