Here are pictures of a combination mechanical, biological, plant filter using a 30 gallon plastic barrel. I use a 1-1/4" bulkhead for the inlet, 1-1/2" for the outlet, and 2" for the drain. I've found this combination to work best. You can use up to 2" bulkhead fittings on a 30 gallon or 55 gallon barrel. In order to insure there are no leaks use Plumbers Goop on both the inside and outside washers, and use teflon tape on all the external threaded fittings.

If there are any parts of these instructions that you don't understand just click on the email link at the bottom of the page, and ask me to explain. After you get all the pieces cut it would behove you to put it together dry to make sure you know how you want evrything positioned before you glue the fittings.

Here is a link to a picture of one of these filters that was in operation all last year. Koi Village Combo Filter

Parts List For Filter

One Plastic Barrel - Be sure the barrel did not contain any toxic substance.
About 5' of 1-1/2" ABS Pipe
One 1-1/2" Bulkhead Fittings
One 2" Bulkhead Fitting (For Drain)
One 2" Elbow (For inside the barrel for the drain)
One 1-1/4" Bulkhead Fitting
One 2" Tee (If you will be burying this filter you will need this Tee as well as an additional 2" elbow.)
One 1-1/4" Male x Socket Adapter
One 1-1/4" Female x Socket Adapter
One 1-1/4" Male x Barb Adapter (This is to connect the hose to the inlet of the barrel.)
Two 1-1/2" Male x Spigot Adapters
Two 1-1/2" Elbows
One 1-1/4" Check Valve
One 2" Gate Valve or Ball Valve
About 5' of 3/4" PVC pipe
Six 3/4" PVC Tees
1-1/2"black ABS pipe
Plastic nursery pot sized to fit inside the top of the barrel.
One roll of 7' x 100' of "Deer Block" (This can be found in the Garden Department of Lowe's, Home Depot, etc. It's the same black netting used for fruit trees. Use a piece of it to make your bag, and stuff the rest of it into the bag.) If you use a 55 gallon barrel you will need two rolls.

Parts List For Pre Filter

Two 12" lengths of 1-1/2" ABS Pipe
One 1-1/2" ABS Tee
One 1-1/2" x 3/4" Adapter
Two 1-1/2" End Caps

Tools Needed

Jig Saw
Drill with 3/8" bit, and 1-1/8" spade bit.
Fixed blade knife
Large pair of Channel Lock pliers
Sand Paper

These instructions pertain to the type plastic barrels that have a molded top. If using the ones with removable lids there are only a couple differences.

Using a Jig Saw or Roto Zip tool cut the top out of the barrel leaving a small rim around the edge. You can rest the bottom plate of the tool on the top rim of the barrel. If you cut too close to the edge you may run into part of the outside wall of the barrel. Save the top to use later for the bottom spacer.

Decide where the inlet, outlet, and bottom drain needs to be located for your situation. Using the washer from the appropriate bulkhead fitting, draw a circle around the inside of the washer. I personally like the black "Sharpie" markers. They will show up well even on black barrels and nursery pots. Drill a 3/8" hole on the inside of the circle for the blade or bit of the cutting tool. Cut along the outside of the circle so that you can't see any of the mark when finished. If you cut on the inside of the mark the bulkhead won't fit through the hole and you'll have to do some shaving.

Once the holes are cut use the knife to shave the rough edges. You could use sandpaper, but I prefer using the knife first and then use the sand paper to rough the surface around both sides of the hole where the gaskets will go. This will help the Silicone to make a better bond.

This picture shows the hole for the bottom drain. It is better, if possible in your application, to have the bottom drain in the center of the bottom of the barrel, but the side installation will work O.K. Make sure when cutting this hole that you leave enough space from the bottom of the barrel for the bulkhead to be pushed through from the inside.

Use the 3/4" PVC and Tees to make a supporting stand for the spacer you make form the lid. If you look at the first picture you'll see the inlet hole is just below the first ring on the barrel. You want the stand sized so the spacer will be just above the inlet. I can't give you measurements for the stand since all barrels aren't the same.

Once you have the stand made set it on the lid and draw a mark around the four corner Tees and drill holes using the 1-1/8" spade bit. Use the 3/8" bit to drill a bunch of holes in the spacer as shown in the next pictures.

Now it's time to install the bulkhead fittings. NOTE: Most bulkhead fittings have reverse (counter clockwise) threads. Make sure the surface around the inside and outside of the holes are clean and dry. Put a bead of Silicone around the inside hole and also around the bottom gasket on the bulkhead fitting. Push the bulkhead through the hole from the inside. Put a bead of Silicone around the outside of the hole and also around the other gasket. Place the gasket over the bulkhead fitting with the Silicone facing the barrel. Screw the locking ring on the bulkhead fitting (counter clockwise) until it is tight. You may need to use a large pair of channel lock pliers to be able to get it tight. Just be careful not to over do it. Tighten it as much as possible with your hand, and use the pliers to give it an extra 1/4 turn.

Put the nursery pot in the barrel and use your marker to draw a ring on the pot following the outlet bulkhead. Be sure to hold the marker level while doing this so the hole you cut in the pot will line up with the hole in the bulkhead. Remove the pot from the barrel, drill a 3/8" hole on the inside of the ring you drew, and cut the hole out with your cutting tool staying on the inside of the mark this time. When you finish you should still be able to see the mark you made. Drill 3/8" holes in the bottom of the pot like you did on the spacer. The picture below doesn't show the holes because I had already put a piece of poly filter matting in the bottom. This is not necessary if you will be using plants in the pot.

Now you can take a break and allow the Silicone to set up for 24 hours.

Screw a 1-1/4" nipple into the inside of the inlet bulkhead. Screw a 1-1/4" elbow onto it and leave the elbow pointing so the incoming water will spiral clockwise around the barrel. This will help settle the solid waste.

Use a 1-1/2 ABS male x socket adapter to screw into the inside of the bulkhead. The inside threads on the bulkheads are standard (clockwise). When you place the nursery pot inside the barrel, and if you cut the hole in the pot properly, you'll be able to use a short piece of 1-1/2 inch ABS pipe to insert through the hole into the male adapter. Don't glue any of the inside pipe connections. It's not necessary since there won't be any pressure on these joints, and it makes it easier to disassemble for movement or cleaning later. Teflon tape isn't necessary on inside threaded connections.

Place a 1-1/2" ABS elbow on the end of the pipe that extends through the pot with the hole turned up as shown in the picture below. By doing it this way the water that flows back to the pond has to rise up through the bottom of the pot, and any media or plants that you have in it.

One of the advantages of this type filter is you can easily change the media in the nursery pot. When setting them up on a new pond you can use zeolite and carbon singularly or in combination to help control ammonia (zeolite), and toxins (activated carbon/charcoal). Once the beneficial bacteria has become established on the media that you use in this filter between the pot and spacer you can replace the zeolite and carbon with plants of your choice. I use Dwarf Umbrella Palms in mine since they can tolerate a high level of salt when needed for new fish, or in case you are using it for a hospital tank. Never use any type of soil in the pot. Use bare rooted plants, and small stones or pea gravel to hold them down so they don't float up and get inside the overflow. In some cases you may have to use a small piece of plastic mesh to put in front of the elbow overflow to avoid this happening. I must warn you that the roots on some plants like the Umbrella Palm will grow down through the holes in the bottom of the pot, and through the media below it, and if left untrimmed will grow all the way to the bottom of the barrel.

It is best if you can set the filter up so you can drain the solid waste that accumulates in the bottom of the barrel straight, but in a lot of cases this isn't possible. The barrel can be buried up to just before the outlet. By using an elbow as shown in the picture below, and running a pipe up the side of the barrel, you can still remove the bottom waste. The valve should be placed at the lowest point possible.

To just drain the solids, turn the pump off, and let the solids settle for about 15 minutes. Lift the pump out of the pond, and open the valve. If you leave the pump in the pond, even though it is turned off, you may create a siphon, and the water will continue to run into the barrel. The bottom water will be forced out of the barrel by the water in the barrel above the drain. You can use a large hose just for draining, or use a reducer to 3/4" with a 3/4" nipple. A garden hose will screw onto the nipple. You can use this water to water your flowers unless you have salt in the pond water. You can put the pump back into the pond and turn it on to flush out the barrel more. You can also use this method to do partial water changes.

Here is a sketch of how the 2" elbow should be placed on the inside of the barrel for optimum sludge removal.

Below is a picture of the spacer, bag of netting, and the pot as they fit into the barrel. The strip of fabric you see on the bag is used to sew the seam to make the bag. Also shown is the pre filter I make.

This is the best way I've found to make a pre filter for a Supreme pump. You can use it for other pumps with similar inlets. The one shown is made from 1-1/2" ABS pipe. You'll need two 12" pieces of 1-1/2" pipe, a 1-1/2" Tee, two end caps, and a 1-1/2" x 3/4" reducer. The 3/4" fitting is slightly too large to fit tightly over the inlet so I wrap some teflon tape around it to make up for it. It will work better if you wet the outside of the inlet before wrapping the tape around it. For the larger Supreme pumps I use 2" ABS pipe, Tee's, and 2" x 1" reducers. Drill 3/8" holes in the two 12" pieces of pipe. Don't glue any of the fittings on these pre filters.

This is a picture of the filter completely installed and working. The light was getting dim when I took this picture. It was an all day job.

Thanks for stopping by!

Last modified on Wednesday March 8th, 2000