DIY Needle Wheel Protein Skimmer

The Goal:

* Systems of +/- 135 gallons with a medium bioload 
* Sump space required for skimmer: 10 " x 11.5" 
* Height: 24" 
* Reaction chamber diameter: 6" 
* Reaction chamber volume: 1.71 gallons 
* Inlet size: .75" 
* Outlet size: 1.5" 
* Pump: SP3- Euro-Reef modified SEDRA KSP-5000A water pump 
* Pump power consumption: 40 Watts @ 115/120 VAC 60hz 
* Air intake: 660 lph

The Design:   

Assembled:	Breakdown:	Dimensions:

Step 1~ Modify Union If Desired

    The first thing that should be built is the collection cup. The reaction chamber can be cut to size to ensure that the overall height of the skimmer meets your needs and will fit in the amount of space required.

    A standard 2" union will be quite tall which will create a very long neck for a skimmer.

Union Modification      Modified Union

Step 2 ~ Collection Cup

Before	After	Circle Cutter

    The cup shown above is 5-5/8" diameter and 5-5/8" tall. This cup can be found here part# 190-C.

          I drilled a small guide hole in the bottom center of the cup. I then then drilled the guide hole using the same size drill bit that the circle cutter uses. I drilled a guide hole in the bottom center of the cup then used a "circle cutter" (shown above) in a drill press to cut the circle out of the bottom of the cup. BE CAREFUL the cup is somewhat fragile and can crack. Go slow and steady DO NOT force the drill bit or the Circle Cutter.

    If you don't have access to a variable speed drill press, I would use a Dremel Tool or a cordless drill with a "cutting bit".

    The hole DOES NOT have to be perfect as there will be a large sealing surface when gluing the cup the the union/neck.

Step 3 ~ Collection Cup Assembly
 

	I used 2" clear PVC pipe. I found a scrap piece locally.
	If you glue the neck into the union (I did not), be sure not to get any glue on the top of the union surrounding the clear PVC. If you do be sure to quickly clean it off.
	DO NOT FORGET to slide the "union nut" over the neck before you glue the cup. I used Weld-On #16 to glue the collection cup to the union/neck assembly.

Vent The Lid:
    I drilled 4 small holes evenly spaced around the outer perimeter of the top of the collection cup lid. This allows the air that the skimmer inducts to escape through the lid. If you do not vent the cup in some way, the air will build up pressure and force the water level inside the skimmer down.

Step 4 ~ Skimmer Cone

    I found this "cone" at Lowe's while browsing through their plumbing section. It's actually a floor drain with a 2" slip on the other side. Use a short length of 2" SCH-40 PVC pipe to join the union to the cone.

Step 5 ~ Reaction Chamber   

	The reaction chamber is 6" SCH 40 PVC pipe. Now that you have the top of the skimmer completely built it will be easy to figure how tall to cut the reaction chamber. Don't forget to take into consideration the 6" rubber bottom cap. I used approx a 13" long piece.  These caps typically come with a large hose clamp which I did not use.
One can use a table saw, but you would have to create a makeshift jig to hold the pipe perpendicular with the saw blade. Just lay the pipe in the jig, turn on the saw, slowly raise the blade and slowly rotate the pipe until you cut all the way around. A choppy cut will leave gaps between the reaction chamber and the bottom of the cone.

Step 6 ~ Install Uniseals®      

3/4" UNISEAL® Skimmer Input	1-1/4” UNISEAL® Skimmer Output

When installing Uniseals® you must cut the hole using an appropriate size "hole saw" described in the chart below. DO NOT use any other type of tool to cut the hole!

 IMPORTANT NOTE:

·        Keep the rubber bottom cap on when measuring how high to install the UNISEALS®

·        The UNISEAL® will easily fit into the hole though the pipe will be VERY TIGHT inside the UNISEAL®. Lube inside the UNISEAL® and the pipe with Windex

·        When pushing the pipe in be careful not to push the pipe too far. It won't want to pull back out.

1. Ensure the hole is clean cut with sharp edges. Irregularities could cause poor seating and ultimately leakage.

2. Insert UNISEAL® into hole with the wide side facing the pipe to be inserted.

3. Make certain that the pipe end to be inserted is clean cut. File the edges so that there are no sharp points to cut the UNISEAL®

4. Using Detergent, lubricate the outside of the pipe end to be inserted, then push the pipe through the UNISEAL® from the large flange side. The detergent will be squeezed off as the pipe passes through the UNISEAL®. The co-efficient of friction of the rubber holds the pipe tightly in place.

Step 7 ~ Glue Cone To Reaction Chamber

    Use Weld-On #16 to glue the cone to the top of the reaction     chamber. Weld-On #16 is designed to fill gaps as well.

1. Use one continuous bead on the top of the reaction chamber

2. Turn the collection cup assembly upside down on a table and apply 1 continuous bead along the inner ledge of the cone.

3. Turn the reaction chamber upside down and carefully set it on the cone (try to center the reaction chamber evenly within the cone).

4. About 15 min later apply a bead of Weld-On #16 in the small gap between the lip of the cone and the reaction chamber.

    Clear PVC glue will do the job, just make sure that there are no gaps between the top of the reaction chamber and the bottom of the cone.

Step 8 ~ Riser Tube

    The adjustable stand pipe will allow quick/easy adjustment of the water height inside of the skimmer. Either repair coupling will work for most skimmers over 25" tall. I used the smaller repair coupling since it is cheaper, locks in position much better and the other repair coupling would not allow me to bring the water level within the skimmer low enough.

NOTE: A hole MUST be drilled in the top of the cap to act as a 'siphon break'. A 3/16" drill bit worked fine for me.

Step 9 ~ Install Elbow

    Install a 1-1/4" 90° elbow and the rubber bottom cap.

Step 10 ~ Attach Pump

FINISHED ~ 1st Day IN USE:

Notes:

• After firing up the skimmer, I noticed some excess micro bubbles exiting the output of the skimmer. I resolved this problem by directing the output into a filter sock as shown above. After that, absolutely no micro bubbles could be seen.

• After a few days I upgraded to a much larger filter sock.

• I will soon be using the GX-2400 Needle Wheel Pump as a 'Recirc Pump' to maximize the skimmer's performance.

2 Months In Use:

Cost Breakdown:

    As you can see the cost for a 10' length of 6" PVC pipe and the pump is the most expensive parts of the skimmer build. Finding a location that will sell 6" PVC per foot may be difficult, but would significantly lower the cost of an individual skimmer. The cost per skimmer is greatly lowered for each additional skimmer that is built.  One 10' length will likely build 5 or more skimmers depending on the height of the reaction chambers. Notice these costs also include 4 Cups Part # 190-C.

Water Pumps:

    Euro-Reef and ASM use SEDRA pumps with a special "Needle Impeller" which produces an excellent mixture of very small bubbles. Many claim superior results using Ocean Runner Needle Wheel pumps.

    I used a Gen X 2400 from Custom Aquatic because they were cheaper. Notice these pumps come with "needle impellers" ! At first I thought that the GX2400 is a tad on the small side,  but after further evaluation I believe it to be just the right size pump and should should be more effective when connected as a 'Recirculating Pump'.

• Part Number: PS-PCGX-2400-NW (635 max gph)

• Part Number: PS-PCGX-4100-NW (1085 max gph)

See What Others Have Done:

Recirculating Skimmer:

    This design allows you to better control the flow rate through the skimmer. The pumps work on a loop that takes water from the body, mix it with air, shreds it (with needle impeller) and pumps it back into the body.

Other DIY Skimmer Links:

Snailman PVC Skimmer     Helpful Info: Skimmer Design 101
 

DIY Protein Skimmer
by Joseph Sellinger

The Mantled Monster - Protein Skimmer

The protein skimmer design and all content on this page is not to be used for reproduction and sale in any way