So lets start at the drain. There are two types.... aerated and non aerated. An aerated drain accomplishes two things. One...it provides great aeration for your pond. But the second thing it does is as the air bubbles rise; currents are created along the bottom towards the drain sweeping all sorts of crud along with it. One of the best 4" aerated drains on the market is the one called "the Koi Toilet". It costs around $225 but is a very well designed and well-made drain. The generic non-aerated drains are around $60. I have used both and like the design of the koi toilet the best.

Now the water enters the filter by way of a 4" drain line. There are so many different kind of filters it will just boggle the mind. I have linked to Koishack's construction forum. There are dozens and dozens of pond build threads there. Many have DIY filters and many have factory built filters. I like the DIY ones.... they work just as well and are cheaper.

Since your pond is not going to be huge, you can run your skimmer line into the filter as well. In the ideal world, you should have a separate filter for the skimmer so you can regulate flow better and this is what I recommend, but I also understand budget constraints! I like Savio skimmers a lot. They are strong and durable but not very cheap. I like the fact that you can stick a UV light right in them without having to do any separate plumbing. Don’t use the Savio brand of UV though….use the one made by Emperor Aquatics (Azponds.com sells them).

For external pumps, check out Sequence. They are one of the best pumps on the market. For submersible, look at Pondmaster Mag Drive. They are tough and will last for years. For the gravity flow set-up I have described though, you will need an external pump. If you want to use a separate pump on the skimmer, you could use a pondmaster mag-drive right in the skimmer box and pump it directly to your waterfall.

For a waterfall, you can use a 100 gallon stock tank and make a skippy filter out of it. The waterfall and the bottom drain lines can flow to it and or you can have just the skimmer line go to the waterfall and let the bottom drain line return under water level to create some nice currents for the fish.

Now for some miscellaneous stuff. The BEST bulkhead fittings I have ever used are called Uniseals. They are only sold by a couple of places. I usually order my pond stuff and uniseals from Aquatic Ecosystems in Florida. Uniseals can be used through the walls of any container or filter box. Electrical conduit threaded couplings with an O-ring also work really well and are pretty cheap, but they take up more room. They have to be the gray electrical couplings because regular white PVC couplings won’t tighten down all the way.

There….I think I covered most of it. Is your head spinning yet? Lol!

Cindy

If the price is right on the used equipment and they are in good shape, you could certainly incorporate them into your build. Use the skimmer and filter falls with a submersible pump just like you would for a smaller pond and put the bottom drain circuit on the bead filter. That would be an awesome set-up!