DIY 4" Needle Wheel Protein Skimmer

The Goal:

	Similar To ~ Pacific Coast Imports RPS-1000  Technical Specifications
			* Recirculating Protein Skimmer * Uses OTP1000 Pump With Needle Wheel Impeller * Systems up to 125 gal * Height: 23.4" * Reaction Chamber Diameter: 4.29" * Water Level Control: Valve * Footprint: 6" x 11" * Requires Feed Pump (1 to 1-1/2 times total system     volume per hour * Retail Price - Approx $219.00 (not including S&H)

The Design:   

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.

    Modifying this union is not necessary, but if you piece all of the components together; you'll find that the collection cup will be VERY tall without the modification.

Union Mod	Before Mod	After Mod

    When I cut the bottom half of the union intentionally left 2" PVC in the bottom half of the union. After the cut was made, the 2" PVC remained inside the bottom half of the 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 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.

Step 4 ~ Skimmer Cone

Before	After

    I used a 4" to 2" reducer coupling for the cone. I carefully cut it down to size using a 12" miter saw. The more you cut off, the the more room you have for a larger reaction chamber. Modifying this reducer coupling is not necessary, but if you piece all of the components together; you'll find that the cone/cup/union assembly will be VERY tall without the modification of at least the top of the reducer coupling.
 

Glue Union To Cone	Attach Cup To Cone

    I used 'PVC pipe cleaner' to prepare the top of the cone and the bottom of the union. I applied PVC glue to both surfaces, placed the lower half of the union onto the cone and carefully aligned the 2 pieces. Some excess glue may squeeze out, just wipe it up.
 

Step 5 ~ Reaction Chamber

	The reaction chamber is 4" 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 height of the 4" rubber bottom cap. I used approx a 13-3/4" long piece. These caps typically come with a large hose clamp which I did not use.
I used a 12" miter saw to cut the 4" PVC pipe. One can use a table saw, but you would want 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 smooth and even cut would be ideal, but it is not critical.

Step 6 ~ Install Uniseals®

    I traced the inside of the Uniseal on a piece of paper, found the center of the circle and used it to punch the center hole in the reaction chamber. I drilled a small guide hole and then used a 2" hole saw to cut the hole. I dropped in the Uniseal, used Windex to lubricate the 1-1/4" PVC pipe and shoved it in. 

   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 ~ Stand Pipe Plumbing

     The adjustable stand pipe will allow quick/easy adjustment of the water height inside of the skimmer. I used a repair coupling for this stand pipe. These pictures show a 1-1/4" stand pipe and fittings. 1-1/4" was too big so I switched to a 1" stand pipe and 1" fittings.

	Top	Bottom	1" Fittings	Assembled

Step 8 ~ Recirc Pump and Plumbing

    For this skimmer I chose to use the GenX-1500 Needle Wheel Pump.

    I have heard that some of the older GenX pumps can have an exposed steel plate sticking out of the epoxy in the back of the pump. I removed the back plate to find out if this one did. This pump did not have that problem.

    The GenX-1500 needle wheel pump has a 1/2" inlet and a 1/2" outlet.   

GenX-1500 Needle Wheel Pump

Modify Recirc Unions:
    I decided to use 1/2" unions to attach the pump to the reaction chamber for easy removal. I want the pump to be as close to the reaction chamber as possible so that the skimmer takes up less space in the sump so I had to modify just about every fitting to shorten up the plumbing.
 

    I used short length of 1/2" PVC pipe and connected a 1/2" union to each end. I then placed this assembly on a miter saw. Connecting the unions in this way will hold the unions perfectly straight and plumb so that a perfect cut can be made. Once you cut the outside of each union, disconnect the unions from the PVC, flip the unions around and reconnect them to the PVC again. Now you can cut the opposite side of both unions.

BEFORE:	AFTER:

Modify 1/2" Adaptor:

1/2" Adaptor	Cut Adaptor	Attach To Union	Attached To Union	Attached To Pump

    Now that the recirc pump assembly is completed, we can choose the proper placement for the recirc pump so we can install the Uniseals. The cone is NOT glued to the reaction chamber.

Cut Holes For Uniseals	Insert Uniseals	Insert 1/2" Pipe	Attach Recirc Pump

Where I Drilled	Drill Hole & Thread It	Screw In 1/4" Barbed 90	Installed Air Inductor

Step 9 ~ Feeding the Skimmer
    One can feed a recirc skimmer many different ways. Most will agree that you want to feed a recirc skimmer with 1 to 1-1/2 times your total system volume per hour.

1 - You can feed it by directing some water from your overflow
2 - You can use an appropriate size pump to pump water through the skimmer
3 - You can tap into your return line and direct some water to the skimmer

    I will be feeding this skimmer using this method.

Modify 1/2" Union
    I used a 1/2" union that is slip on one side (union nut side) and threaded on the other. You can create this combination while in the store or just buy 2 unions (one threaded and one slip).

1/2" Union	Cut With Miter Saw	Threaded End	Glue In PVC Nipple	Valve and Fittings	Valve Assembled

Cut Hole	Insert Uniseal	Install Valve/Union

Step 9 ~ Glue Cone To Reaction Chamber

FINISHED:

(More Pics To Come)

       

Cost Breakdown ~ COMING SOON:

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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