DIY skimmer design

[georgeortiz]

Here is a good website for those interested in making thier own skimmer. I have used the information on this site to make a pretty good skimmer.

Even if you do not want to make your own this site is good for the beginner to understand how a skimmer works.

http://www.hawkfish.org/snailman/skimmer101.htm

[matt]

I've been saying all along that these are probably the most effective skimmers around, but they're very inconvenient. One, they're huge; for a sizable tank, you need one 5 or 6 feet tall. Bigger for a big tank. Two, they should be driven with piston air pumps, which are VERY loud. I guess a smaller one could use several big aquarium air pumps like the old tetra luft. Basically it rules out having the air source be in a living space. Three, you need to either invent a much more reliable and durable airdiffuser, or be prepared to change several large woden airstones every few weeks.

If those obstacles can be overcome, these are probably really something. They overcome the biggest fault in design of almost every skimmer on the market; not enough contact time. My beckett skimmers somewhat address this by using a high volume foam tube and running the water level near the top of the tube. So, there's enough water in the skimmer that there's decent contact time, and the centrifigal force of the water movement tends to force the foam up; this means that organic laden water spends more time in the tube swirling around, and clean water, which is heavier (not as much foam created) tends to drain down the middle of the tube. But these huge airstone skimmers have more volume, and the through-flow is something like 100 gph rather than 1000gph.

If I could find the right air pump, that put out the pressure but didn't sound like a compressor, and a diffuser that lasted more than 2 weeks to a month, I'd build one. I couldn't use it in my house, but I'd still like to see one in action.

[georgeortiz]

Matt,
True it does take alot of space. I did have the luxury of having space to hide the skimmer. I will post pictures of the skimmer when I get my setup going. I used the information as a basis though for making my skimmer which I designed to control a couple of the skimmer varialbles.

[wkopplin]

I have the space and have no noise considerations. Makes no difference to me how noisy it is, but I do not want to change airstones every week.

[georgeortiz]

Here is a pic of my down draft skimmer. I know that most people feel it is a pain to change the stones but, the way I feel about it is I made it and It works.
If I had the money to go out and buy all the "top of the line" equipment I don't think I would have as much fun with the hobby. Half the fun is understanding how everything works and if you want being able to build your own components the other half is getting the reef system running in harmony and looking nice. Research Research Research!

[matt]

It looks good! It's not a downddraft skimmer, though, those are something completely different. It's a countercurrent airstone skimmer. I'd like to see it in action.

Matt

[georgeortiz]

Sorry,
You are right. It is a counter current skimmer.

[matt]

George;

Did you use extruded acrylic for your tube? How is the joint between the tube and the bottom sealed? And, it looks like you ran some PVC through the tube near the bottom, I suppose for the water outlet. How did you seal around the PVC? I'm asking because all of these are potential leak spots. Obviously you're going to run this thing external. Have you filled it with water yet? Also, your valve on the water input (red handle) does it have any metal parts?

[georgeortiz]

Matt,
There are no metal parts on my skimmer. I did use Acrylic for my tubing. By extruded though I am not sure what you mean there. I have tested the setup and there are no leaks. I sealed around the pvc with aquarium sealant. This is the first skimmer I have built and I am pretty please with the results. Maybe later I can try my hand at building a beckett skimmer.

[matt]

Sounds good, George. If you ever have a problem with leaking around the PVC as it goes through the tube, you can fix it with weldon #40. Typically silicone will not adhere well to acrylic. Extruded acrylic is manufactured differently than cast acrylic; those are the two types of tube. If you paid less than $30/ft for 6" diameter tube, you can be sure it's extruded. Cast acrylic holds up better under water pressure, but 90% of aquarium projects are made with extruded, so i wouldn't worry about it at all. I would be concerned about sealing PVC to acrylic with silicone, though, especially at the bottom of a big tube filled with water. Just keep an eye on it...

Can't wait to see some photos of the skimmer in action! What are you using for an air diffuser and air pump, if you don't mind me asking?

[georgeortiz]

Matt,
I am using 2 lee skimmer stones. I can expand this if neccessary. I also have some coralife stones as stock to see if there is a differnce in performance. I am using a large two outlet air pump. I don't have the model number on it but, it works beautiffully.