Many of the babies had begun sneaking over to the "scary" side of the pond and were hanging out with the big fish without getting eaten, so we removed the divider on August 1st. Since that time, everyone's been thriving just fine, thankyouverymuch. The big guys continue to eat like pigs, but they're not eating the little guys so they are growing and growing. Except for some, which is really quite odd. There are babies ranging in size from 3/4" up to about 3" and I have absolutely no explanation as to why this would be so if they all hatched within a few days of each other.

Aaanyway...

I recently put together instructions for some ponder friends on what Steve has done to build our beautiful biofilters and I thought I'd upload it all here to save it in perpituity.

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I've had my pond for about 12 years now. In that time, like most "ponders," I've learned a ton through trial and error. After years of slogging through gallons of gross fishiness, cleaning one kind of filter after another and still looking for my fish in murky water, I was really - dare I say desperate - for a solution. In one of my online pounding groups I began to hear about something called a Skippy Filter and here's what I found on the Web:
http://skippysstuff.com/biofiltr.htm

If you read through that, you’ll understand the philosophy behind what Steve ultimately designed. Here's a shot of what we have today (this is one of two in our pond):

The innards are very similar to what you see described in the Skippy Filter write-up, only we’ve made it soooo much prettier than a 100 gal. Rubbermaid horse trough! (We used the trough at first and have since dismantled it in favor of the pretty pots.)

So…

Your first step is to understand how many gallons of water your pond holds. If you don’t already know the answer, here’s a calculator you can use to estimate:
http://www.pondcare.com/reference-center/pond-calculator/index.aspx

The rule of thumb for selecting a pump is to circulate the entire volume of the pond once every two hours. More often won’t hurt; less often will.

What you’ll need to figure out is what you can use for a pot that will withstand your local climate. Will fiberglass hold up? Some kind of metal that won’t leach anything weird into the water? Alternatively, you can buy a small heater and keep it running during the cold months. That should keep a ceramic pot from cracking.

Here are some drawings to show you what we did:

This shows the plumbing, obviously. The length of the center riser (6” in this drawing) should be adjusted to accommodate the depth of your pond and the height at which your pot will finally sit once you figure out what you want it sitting on.

Here’s what it looks like from above, looking down into the pot:

Adding the elbows makes the water swirl as it percolates up through the filter media (more on that below).

We have the pot sitting atop cinderblocks, with the plumbing sneaking between the blocks to come up the center, and capstones on top the blocks for a finished look.

Now, as for the filter media, we have found the best option is an industrial-strength grill-cleaning scrubby pad from a restaurant supply store. They’re very heavy duty, black scrubbers that look like this:

Do NOT use anything thin like these:

They’ll just compress and inhibit proper flow.

You might find things on the ‘net that talk about using swamp cooler pads. Don’t do that either. They’re made of organic material that will break down and gunk up the pond. Use the heavy duty nylon scrubbies. They aren’t cheap but they’ll last forever!

Once you get all the plumbing hooked up and tested, and your pot is situated where you want it, toss in enough scrubbies to fill the pot about 2/3 to 3/4 of the way. Just jumble them in – no need to stack and probably better if you don’t.

The plants go on top of the scrubbies. Talk to your local garden store or other ponders in your region about what kind of plants to use. You want something with a feathery root structure. In the pot pictured above we have black rice and water hyssop. There are many, many options. We like to use some large stones to weigh everything down until the plants have a chance to really put down their roots and grab onto the scrubbies.

That’s it! Now all you need to do is sit back and enjoy your fauna while your flora do all the work!

Remember: You must never clean this filter. Cleaning it will mess up the biological magic and defeat the whole purpose. You won’t have to clean your pond at all. When green stuff grows on the sites, it only makes the pond look more natural, and the fish will love to munch on it.

Let us know if you have any questions about getting it all together and how this works out for you if you decide to build it.