My pond is 12,000 gallons and is in full sun. Every year my water turns green and stays that way from July on with no visibility. I have a bio falls filter from Aquascape and a large sand filter with a u.v. light. A friend of mine says he will put in a bog (free of charge..can't beat the price). I can't keep any plants within the pond as Koi pull out as fast as I can plant. By the way, my pond does NOT have any shelves, just a straight drop off to 5 and 6 feet. I think a bog would be very helpful and a nice eye pleasing addition. my friend says he will put in IF I come up with the plan. I have looked thru back issues of the Newsletters and other litature available, but nothing on bogs. Bob, can you help me with advice as where I can find information for my size pond? Thanks A Bunch. (First Answer)
(sent later)
Now I am so eager to get started, my poor "friend" has no idea what he volunteered for. One final question, and I promise not to "bug" you (at least for 24 hours). I have always said my U.V. light was not adequate, but my last pond guy always disagreed with me. Within the last 24 hours the light has burnt out and the unit is leaking a good amount of water. Great timing! As now is the time to replace the entire unit. For my volume of water (12,000 gallons) what size unit do you recommend? (Second Answer)

Answer #1:

For our definition of "bog garden", what we are looking for is a place to set large quantities of greedy pond marginals and decorative marsh plants where the fish can't get at the roots. Flow through this area should be steady, but not as fast as your streams. We're looking for maximum exposure to plants and relatively permanent plantings. What we want to do here is soak up all that nitrate from the filters and leave nothing for the microscopic algae.

The fact that you have green water with a UV unit tells me that either the UV bulb is shot ( they rarely last more than a single season, even if they still glow bluely ) or the UV unit itself is just not big enough to handle the volume of your pond. You should check both.

Back to the bog. It does not have to be next to or indeed anywhere near the main pond, except where the water flowing out of it enters, perhaps as a small stream. It should be wideish, (one to two yards) and can meander anywhere, so long as it's all downgrade enough at the tag end to reach the pond. Shallow is good, 12-18 inches, with occasional deeper areas to plant hardy water lilies. Liner bottom,( and here you want to cover it with smooth river rock, since there will be no koi in it.) with reeds, grasses, cattails and blooming perennials everywhere. Maybe some expendable goldfish.

Feed it either from the falls or from a separate pump, maybe plumbed from the skimmer, leaving the falls to run off the bottom drain. Since you are using this as a bioconverter of sorts, you will need to put a significant fraction of of your pond volume through it each hour.The flow should be brisk enough to prevent mosquito reproduction, slow enough to allow lilies to thrive. Berm it at the outflow end to maintain the depth you want, and let the outflow over the berm (like a beaver dam, maybe?) form a stream or other feeder back to the pond.

In winter, let it freeze up, like a natural stream. If you've put hardy perennials into the bog bottom, they'll all be back in the spring.

Don't worry about amphibs. If you build this right, they'll come.

Answer #2:

The person to talk to is Mike White, but in general, you'll want a UV setup with at least a 2-inch feed and drain port, and a high-intensity bulb. These come in a variety of sizes, and I'm not the expert here. Tony Malone has a bank of six of these monsters, constructed of heavy-duty PVC and about six feet long apiece. He bubbles carefully metered air through this manifold, and generates just enough ozone to keep his dissolved organics and sludge at bay. Charlie Ruegsegger designed the thing, and the airflow conversion tables and ozone production graphs are things of rare beauty and terror.*Not* for the beginner, or even a fairly seasoned hobbyist. This is true *Geek Zone* stuff.

Bob Passovoy
President MPKS

"Older than Bronze, Younger than Dirt"-Capricon 2002 Auction staff