You might try posting your question on the "Ponds & Aquatic Plants" forum of GardenWeb. There is occasionally discussions on bog/veggie filters there. Below is a link to a page with a description of the bog-type veggie filter we built a few years ago. Good Luck!

Sherry

Here is a link that might be useful: Bog Filter

My 3 yr old pond a 40' X 70 ' has had green water problems for most of it's 3 years. It looks great until hot weather, then pea soup. I am considering a bog garden. I have 7500 G pump, skimmer and bio falls with filter media. This would supplement my current filter system with a seperate pump. I have plants, a few fish, trapdoor snails and lots of rocks. over the liner. I have read the posts on the bog topic. Is there a site for construction of the clean out PVC section needed for the perforated PVC that goes to in the bottom of the bog. I do not want to construct one and then have it clogged. Is it a good idea to have a small drop for the water (a waterfall)as it re-enters the pond after being filtered by the bog. I am on a small budget so I need some help with cost effective ideas. Can you use a seperate flood pump to pump water into the bog?
What do you do in the winter with plants that are rooted in pea gravel, I am a zone 4-5?
I appreciate the time others take to write in and give us newbies a little advice.
Wanda