Bog filter for Daisy

[Paul zone5]

Daisy,
You have been posting interesting photos about the progress of your cistern pond. In the one posting you mentioned your homemade water filter. You expressed interest in my suggestion of a bog filter. I've finally found a good site that explains how to build one that doesn't involve deep excavations. It should be possible to scale this bog. The site is http://www.instructables.com/id/Hydropo ... Recycling/

"It essentially uses the same techniques employed in aquaculture. Use bacteria that are attached to biomedia to clean the highly oxygenated water passing through the media. We use alfagrog media for this. It has a high surface area and good void capacity. The added bonus to this system is that by placing a gravel bed over the top of the media we have been able to produce an ideal environment for growing those difficult to propagate plants. The moisture loving ones that fail at the first sign of drought"