I used a rubber sheet cut to fit behind the flange with the hole for the pipe barely large enough to fit snugly around the pipe. Most people cut an X smaller than the pipe diameter since the rubber will stretch to fit. I used a silicon type adhesive/filler to attach this gasket to the filter body although there are a number of products that would work as well. It doesn't have to dry hard. In fact it is better if it remains flexible. It has been in place over 10 years now. The flange can be tightened down to compress the rubber to prevent leaks. Check the plumbing section for DIY rubber sheets. They are usually about 4x4 inches.

wow! Water cleared in about 36 hours. I should have done this years ago. the hardest part for me is going to be to not clean out the bio-filter. I open the lid and see all that green algae and I want to clean it out. I will not clean, I will not clean, I just have to be strong. Hopefully it will stay clear. I sat by my pond for about 2 hours tonight just watching the fish and turtle swim and the frog eat June bugs. It was great. Everyone should build one of these.

Once tannin is present, it doesn't go away by itself. It must be either diluted by water changes or removed by the absorption quality of Activated Carbon. Maybe there are other ways to do it but I doubt they would be very practical. Tannic acid can play havoc with PH levels too and it can have a nasty smell like dead swamp or rotten organic material since that is what makes it. I recently bought a half gallon container for $12.00 at Pet World. Garden centers sometimes carry it at low cost for African Violets. I have found it for various prices at many stores. A half gallon will last a year or more in my pond which is under very large red oak trees. I place a cup or two in a perforated planter and put another perforated planter on top of it to hold the carbon inside. It goes in the top of the Skippy with either some rocks or a potted plant inside to hold it in place. A muslin bag works too. I get the largest size chunks of carbon I can find because it is the surface that collects the molecules that make the stain and odor. When it seems to lose its effectiveness, I lightly crush the chunks and it starts working again because I have exposed fresh surface area. I can do that 2 or 3 times if I don't mash it too much the first time. Powder works fast but doesn't last long. The difference in clarity is amazing. The bottom and the fish colors seem to pop out at you.

The bio filter I made from a new plastic paint bucket and lid loooks just like Jeffs, miinus the airpump inlet. But I have a problem I hope someone can help me with. In order for the water to flow out into the pond, the bucket must be several feet above the pond. So to conceal the bucket I will have to build the rocks a lot taller than I would like. Seems like the pump will pump the water to the bucket, but hasn't got enough umph to push it up-hill through the tubing to the 'falls'. I would like my bucket to be on the ground, (just above the pond), and have the water run up the tubing to the top of the rocks. This way I won't have to built a 3 ft. tall wall to hide the bucket. Another question. Do I need a lid on the bio filter? If I made a wider, lined, box, could I leave it open, or must it be closed to work? Seems like I remember seeing one like this when I researched construction of a bio filter on Garden Wed a few years ago, but can't find it now.