New DIY Aspirating Venturi Skimmer Design

[Brian Prestwood]

We've been building this skimmer at the Marine Aquarist Roundtable of Sacramento (MARS), www.marineaquarist.org for a couple of years now.

We're looking for feedback. Please let me know if you any problems with the design, ways to simplify construction or ways improve performance.

It is a counter current, recirculating aspirating venturi, tangential injection design.

In other words, the water from the tank enters near the top of the skimmer and exits at the bottom. The venturi is on the intake side of the pump. Both the pump intake and exhaust are plumbed into the body of the skimmer. The exhaust of the pump is plumbed so that it enters the chamber tangentially. This creates a whirl pool effect the increases contact time.

Recirculating venturi designs dedicate a pump on a closed loop to foam generation. Another pump is required to pump water from the tank to the skimmer. I put a "T" in my main circulation loop to pump water into the skimmer.

Here's a diagram of the basic skimmer...

http://www.marineaquarist.org/Portals/9e47b9dd-73aa-4c61-8ad9-7eadcacbad35/SkimmerBlockDiagram.jpg

Please note that the 1/4 vynal tubing that runs between the needle valve (#29) and the venturi (#1) intake isn't shown for clarity.

and here's a parts list...

MARS DIY Skimmer Parts List (http://www.marineaquarist.org/Portals/9e47b9dd-73aa-4c61-8ad9-7eadcacbad35/Skimmer%20Parts%20List.htm)

Construction is fairly simple. You'll have to drill and tap four 1/2 inch holes and one 1" hole.

If you opt for the hanging model you'll have to cut four rectangles of plexi-glass and drill (no tapping) several small size holes into them. The two larger sheets will also require a 4.5 dia hole.

Here's a picture of the previous incarnation (please pardon the mess)...

http://www.marineaquarist.org/Portals/9e47b9dd-73aa-4c61-8ad9-7eadcacbad35/Gallery/Skimmer/Skimmer.JPG

Here's a diagram of the two pump version...

http://www.marineaquarist.org/Portals/9e47b9dd-73aa-4c61-8ad9-7eadcacbad35/SkimmerBlockDiagram2.jpg

We've been discussing it on our club forum here on RC. That thread has the answers to a lot of questions people had...

MARS Forum Thread (http://archive.reefcentral.com/forums/showthread.php?s=&threadid=309597)

[raven898]

where did you get the clear pipe?

[Brian Prestwood]

From Aquatic Eco Systems. It is 4.5" OD extruded acrylic. It costs $13/ft. Clear PVC from Savko is $18/ft. We're probably going to use clear PVC on the next batch we build.

[Dano]

What pump did you use? What kind of GPH is needed?

Thanks

[Brian Prestwood]

Dano

We're using the Kent Turbo Venturis...

Kent Turbo Venturi (http://www.kentmarine.com/vv.html )

Last time we built the skimmer we used the Sea Bee pumps with the needle wheel impellers. They didn't last very long.

At least one member built his with a non-needle wheel pump from the start. It worked very well.

I replaced my Sea Bee pump with a very strong non-needle wheel impeller pump. It worked so well I had to move the venturi from the intake to the exhaust side to avoid foam outs.

I'm in the process of testing the Mag 5 with the 1/2" Kent Turbo Venturi. I should be done this week.

Also, I thought of a way to mount the hang on collars that I think will work much better. I've updated the diagram and

part list to reflect the design change.