Bog Filters - anyone use one?

[Newt]

Doing some reading and ran across several topic dealing with using a bog filter. Basically an area with 1/4 to 1/3 of the surface area of your pond, dug to 3 feet depth, lined, filled with 2 feet of pea gravel, and water from your pump into the "bog" at the side opposite your pond. An outflow back to the pond set to maintain an 18 inch depth of water giving you about 6 inches of gravel on top of the wet part.

 

Lots of plants enjoy this sort of conditions and when they root into the wet part, they will do a nice job of filtering and using the excess nutrients and the gravel will give huge surface area for the bacteria needed to deal with other stuff you don't want.

 

I liked the idea because it should need no care after you get it planted. And as soon as the rain stops for a day or so, I plan to start digging one.

[John S]

I have seen diagrams and photo's of pond filters that consist of a channel running along the top of the pond side (raised pond), filled with gravel and seeded with water cress. Not only do you get the filtration, you have a regular crop of salad leaves too.

[Newt]

John - I've seen those as well and they are an interesting idea. I opted for a detached area because I wanted to retain better access to the pond than I thought I'd get with the filtration along the edge.

 

Might be interesting to do a combo thing though and have some of the "bog" area along the pond edge.

 

As to the crop part, the idea with the detached bog filter is to load it with plants.

[chesters1]

no only ponds but also to "clean" sewage, in past times the "filters" were reed beds and a eco form of septic tank , i think the use of toilete paper nowadays probably were too much for them to cope with

[Ed Matysiak]

I once saw this being done on telly. It was that programme where the family wanted to build a house that was as eco. friendly as possible. They had a pond in the back with this sort of filtration. It looks good too compared to a big black box.