Homemade Pond Filter

A homemade pond filter has to take into account several important functions and characteristics.

To begin with, there are two kinds of filters recommended for ponds of 800 gallons or larger.

Two Kinds

The first is a skimmer type of filter that removes the large floating debris. Think of a pool skimmer that removes leaves and other "stuff" that could plug up pipes, plumbing or the main filter system (maybe causing it to overflow or run the pump dry)

The second is the bio-filter where the secondary filtration takes place along with the biological filtration.

Building Your Own

Here are some thoughts on building your own home made pond filter:

You need a very heavy duty, large plastic container that will not crack or degrade in the cold. You can usually find these large containers at the big-box stores for a reasonable price. Rubbermaid sells some very good heavy ones and they come complete with a lid - and you'll need a lid on your home made pond filter to keep out plant debris and animal pests.

You'll require inlet and outlet fittings for your connecting pipe. I successfully used pool fittings here. They worked very well and are easily obtained. You'll need one per filter (the skimmer takes water in and pumps it out through the outlet- the biofilter filter takes one inlet and lets the water flow out into a waterfalls) Note that these fittings are identical.

Fish Grade Silicone

You'll want to purchase fish grade silicone for a sealer. (see your local pet store) Other sealers might not be fish safe and you don't want to lose fish to save a few bucks. This is about making your own home made pond filter - about keeping your fish safe (while saving a few bucks).

The pump sits in the skimmer filter (which is why you need to get rid of big debris so it won't clog up the pump). This means you have to epoxy ledges to the sides of the home made pond filter container to hold your primarily filter from sagging down into your pump area.

Whatever material you select to hold your filter (check local furnace installers for fiberglass type of filters or construct your own using aquarium parts). One system I found useful was to epoxy a metal grid to the plastic container (use an old BBQ grill) and then lay aquarium filter material or furnace filters on top of this. Alternately you can expoxy some wood to the side and lay a grid or screen on top of these wood strips.

Pump Sits On Bottom

Plumb the pump, sitting on the bottom, so that the outlet goes out the side of the skimmer as high as possible. This will help eliminate siphoning if your pump stops.

he biofilter is plumbed into the bottom so the water comes in as low as possible. It flows up through the biofilter material and then flows out of the pond.

Spa Grade Pipe

Use spa grade pipe. There's no sense saving a few pennies here. It will crack often enough in cold weather - the cheap stuff cracks regularly. And its one thing to make a home made pond filter - it is another thing to have to dig up and replace the plumbing every spring.

You can use any kind of material in the biofilter or home made filter you like to provide a surface for bacteria to live on. Lava rock has been used by many folks building a pond. You can also purchase the bucky-ball type of material from pond suppliers (they'll be roughly the same price or the plastic will be cheaper) Put these in a nylon bag of some kind so they can be easily cleaned at the end of the season (fishing them out is a pain in the anatomy).

Keep Inlet Free

The trick with the home made filter is to ensure the inlet is free and clear so the water can get into the filter (from the skimmer) easily. And then to suspend the biofilter material (can you say epoxy another ledge) over top of the inlet to provide a settling space for any other garbage that made it through the skimmer filter.

You can almost construct both the skimmer and filter assembly the same when it comes to suspending a filter. On one you'll be suspending a filter material to collect leaves and debris (the water will be coming from the top) and on the other you'll be suspending a heavier material and the water will be coming from the bottom. (remember the skimmer puts the water out the top and the biofilter takes it in at the bottom)

And that's the word on home made pond filters.

Save Some Work

Let me suggest two things that will save you an incredible amount of work:

The first is to go to a pond place that sells larger bio-filter systems and skimmers specifically for ponds. Take a good look at these. You want to copy them as much as possible.

Second, consider the cost of these purchased systems against the cost of doing it yourself. Unless you are very handy, you may find it more practical to purchase a system that is guaranteed to work and that will require much less horsing around. It is up to you to decide if you want to play around with the home made pond filter and pump plumbing or simply enjoy the pond as much as possible.

Shopping Resources for this Page

You can get parts for your homemade pond filter and see complete system pricing here