www.KoiPondCentral.com 
DIY settling tank
DIY pre filter

Vortex Barrel settling tanks with Pre-filter.

The How-to.

Crud that free flows to the barrels in this design settles out very well at the bottom.
(See Diagram 10.) Polyurethane 55 Gal. barrels were used.

It could be a vortex design IF YOU added cement in the bottom, and tapered from the sides to the center. At the center, you would install a bottom drain which is controlled via a knife valve. This permits much better clean out. (Tip: Make cement surface smooth to permit crud to slide down)
1 Two barrels for settling, one for Pre-Filter. (See fig. 8)

Measure down 5 inches & cut the "Exit hole" to fit tightly around the ABS flange. (Flange is an ABS  floor mount for toilets. See picture 4 below)

Then measure down 17 inches and cut the "Entry hole" to fit tightly around the ABS flange. (Flange is same type. See picture 4 below)

(55 gal. Polyurethane barrel drums can found cheap ($5.00) at your local car wash. Rinse well.)
2  Dry fit all parts prior to assembly!! This is important!!!

NOTE: The elbows that are used on the inside and are connected on the "Entry Flange" require the Entry flange to be lightly filed on the inside until the elbow fits and inserts tightly. (This can be done later when attempting to insert the elbow).
3  With 4 holes drilled for bolts (Stainless Steel Bolts, washers and nuts ready), apply a 1/2 inch bead of silicone on the inside of barrel.

Use lots of Silicone. GE II 100% Silicone. (Another product that should be considered is Dow Corning 795. Claimed by professionals that is sticks to anything and is better the the Silicone. Silicone was used in this project.)
4  Now caulk 2 rows of Silicone around the inside of the flange and add extra in the four bolt hole locations.

Use lots of Silicone. GE II 100% Silicone. 
5 Insert the flange and the four bolts and washers. Use washers on the inside and outside. On the outside, tighten on the nut. Silicone will ooze out. Smear this extra around the flange to help seal the barrel and the flange. See picture #6. 

Use lots of Silicone. GE II 100% Silicone. Be sure to permit 24 hrs drying time prior to running any water.

Also notice the light filing mark needed on the inside of flange where the elbow will be dry inserted later. (DO NOT GLUE the "inside" Elbow! Refer to picture 9.)
6 When bolts are tightened, the barrel flattens and silicone oozes out. Smooth the silicone around barrel hole and leave silicone covering bolts heads. 
7  Board on the floor which, is leveled prior to adding gravel and barrels.

A nice improvement would have been to cement the floor and walls. Later I found that the moles have brought in dirt to mess this up. Darn moles!

Notice the two 4 inch ABS pipes which free flow pond water from the ponds bottom drains.
8 Barrels set and ready for connecting. The white barrel is the pre-filter. The two black barrels are the vortex settling chambers. 

1800 GPH is max for the amount of water flow and still get any settling of crud.

A nice improvement would be to have bottom waste drains installed in each barrel. Worth the extra effort if possible. I use a submergible pump to clean out settled crud and hate doing it. Sure wish I installed waste valves!

9 The "slip fit" elbow provides the directional flow or vortex action needed for crud to settle to the bottom. The Elbow does not need to be glued in place. Nice being able to adjust angle or remove during cleaning if needed. (This is the elbow referred to earlier in picture 5 about needing some filing in order to fit. (Install an elbow in both barrels.)
10 The crud build up prior to cleaning. Also notice that the white pipe in the lower right corner is the over-flow pipe. This is the ponds over-flow since we have so much rain in Washington.

Also notice the top 4 inch exit pipe has a slip fitted converter. (Not glued) This has a threaded female which, I can thread a plug into. When I plug up one of the two barrels, the other barrel flows twice as fast. Do this to help clean out any sediment in pipes.
11 Over view of completed install. 

Another nice feature with having these barrels is when adding Baking soda or other chemicals. By adding into one of the barrels, the fish are not hit with a major dose. The added chemical is slowly entered into the system and pond. 

Should a chemical be one that will disturb your bio-filter, then bypass the bio-filter using valves till it is safe to continue filtering.
12 The 2-inch 3 Way valve mounted in front of the pump provides flow control from sources. One source is the pre-filter which is supplied by the drum settling tanks. The second source is the Skimmer. 

The 3-way permits me to choose any percentage from either source. It also can be shut to the close position  in order to remove the pump if needed.
13 All nicely tucked away. Hinged access cover roofed with extra EPDM liner. Small access lid to adjust the 3-way in front of the pump and other valves. 

The Advantage Bead filter off to the corner for Bio-filtration. The U.V. Light is also mounted along the fence. (5" black vertical tube just above the blue fish tray.) 

The white posts will be shortened and other taller posts bolted to them supporting the future vine arbor over the wooden wall. The wooden wall acts as a back to the waterfall on the other side going to the pond.
14 The handy access lid is much lighter then the main lid. Often I only need to access the valves.

This system works! An improvement would be to add the barrel bottom waste drains, and possibly even pour a concrete vortex shape in the bottom of the two settling drums. Consider about 8+  inches at the sides sloping to the center. (Make cement smooth to help crud slid to center.)

www.KoiPondCentral.com

15 Barrel # 3 - The Pre-Filter

The last drum is the pre-Filter. Install the 2" bulkhead about two inches off the bottom. Can be higher and should be on a flat area of barrel.

(Review new and better design for media support in the picture below - See #16) Old Method that is brittle - To support the filter material, buy a 2'x4' plastic florescence light lens grid from your local hardware store which has 1/2" squares openings. Cut this in a circle and support it off the bottom using 3 scrap 4" ABS pipes cut about 8 inches in length. Zip tie plastic grid to ABS. (The plastic lens support can be 4 inches less in diameter in order to get into the drum.)

Then add a layer or two of fine Poly-Flo media and one or two layers of coarse Poly-Flo filter media.

 

Don't forget, usage of a U.V. Light should be installed after the Bio-Filter... 

Better design for filter media support in the last Pre-filter barrel.#16

 Purchase the needed 1/2" PVC parts to build the leg supports shown in the diagram to the left.

Requires:

 8 - Elbows, 1/2"

 5 - 4-way cross fittings, 1/2"

 1 - Length of 1/2" PVC

Lay out the parts first on a media mat that fits in the barrel, then measure and cut the PVC as needed to create the grid shown. The legs can be any length needed to raise the frame off the bottom to clear the bulkheads in the side close to the bottom. The grid supports the media mat much better then the design in picture #15. In picture #15, we found that the plastic grid broke sometimes when removing the heavy crud filled media. 

Drill a couple of small holes in the top PVC frame to let the air out. This will help the frame fill with water.

Feel free to contact us for any details you may have questions about. Glad to help in anyway we can! 

Many people around the US have made this design with great success. Consider pricing all needed materials 1st. 

Billp@SkagiTek.com                         www.KoiPondCentral.com