Plumbing Question on DIY Counter Current Skimmer

[iopusl]

Ok I recently stumbled upon Shane Graber's Skimmer Design 101 web page. I have finally have had enough with my Seaclone and decided to use this page as a guide to build my own 4' Counter current protein skimmer.
My display tank is a 55g with a 20g long used as sump/refugium. I have a Mag 3 pumping from the fuge back up to the display at a about a 3' rise with a generic overflow going back down. The Mag 3 at 3' is rated for 300gph. Following the Explanation on Graber's page, the flow through a counter current should be around 55gph. The flow rate should be 3/4 the total gallons.
55+20=75 * .75 = 56.25
My original plan was to have the skimmer fed straight off the overflow of the display. But the 300gph is a hell of lot more than 55gph, and I'm not going through all this work so that this skimmer is ineffective. So now I have to divert alot of the water coming out of the overflow somewhere else besides the skimmer. This is what I came up with:
Have the overflow from the display run into a T adapater on its side first used as an overflow, and have the bottom of the T feed the skimmer through a ballvalve to reduce the flow on the skimmer. Then I plumb the output of the skimmer straight up so that it is a 1/2" lower than the T overflows output. I figure this way the skimmer shouldn't have any problems in competing with the T overflow for water.
Anyone out there done anything even close to this ?
Will this Work ?
Is this really stupid ?
Am I missing something ?
Any input out there is appreciated
Thanx

 

[squidd]

Yeah...
The "theory" is sound but I'd be interested in where he got his "math" from...
55 gph in a 4' skimmer will give you almost no bubbles (actually no bubbles) ...
You will need a lot more "drop" from the tank to the skimmer "input" to get the velocity needed for proper opperation...
Perhaps your drawing is out of "scale", but it will not work as shown...

 

[iopusl]

Squidd, I'm sorry I forgot to mention there will be 3 airstones on the bottom of the skimmer. That should give me plenty of bubbles.

 

[squidd]

Then the slower current "might"e OK (as a downdraft...) Suggest using a wood airstone(s) for "finer" bubbles...

 

[iopusl]

Thanks Squidd. Sorry I didn't explain better.

 

[darknes]

iopusl,
I built a skimmer very similar to yours. I may have even used the same site you used for ideas.
Mine works great!
I just want to give you a few tips that might help:
-As Squidd said, make sure you use wood airstones, and not the plastic or ceramic; they create much finer bubbles which is what you want.
-Make sure you can take the thing apart easily so that you can replace the airstones.
-Instead of silicone, I found plastic epoxy to work much better; It gives a much stronger hold and won't leak ever.
-Make sure your airpump is strong enough. With a four-foot tall water column, you need a strong pump to pump air up; I recommend the tetra-tec deep water pump.

 

[darknes]

I add a few pics for you:

 

[squidd]

That's an interesting looking "setup"...
Don't know that I've subliminal "Seen"hint it on any of the "sites"another one
:thinking:

 

[darknes]

Originally posted by Squidd
That's an interesting looking "setup"...
Don't know that I've subliminal "Seen"hint it on any of the "sites"another one
:thinking:
I'm not sure I get what you are saying.

 

[iopusl]

Darkness how does yours work ? Plus thanks for the suggestion. I just got a tetra tec deepwater pump.

 

[hondotech]

How about a link to the site?

 

[darknes]

@iopusl, I'll try to explain it using the numbers on the attached diagram (sorry for the quick sketch)
White arrows indicate water flow, and yellow arrows indicate air flow.
1: Water is sucked in from the tank by gravity through a U-shaped connection near the surface (can't see)
2: This red part is a ball-valve which I use to control the inlet water (never really use; always wide open).
3: This hook shape in the pvc is supposed to be when I wanted to drain the skimmer, I planned to shut off the inlet ball-valve, then open this cap so that the pump could suck all the water out of the skimmer (Not needed; I guess I miscalculated that one).
4: The water is fed into the main tube by gravity (as the pump pushes water out of the skimmer, the siphon fills it back up here). Water level ends up being a few inches above this point.
5: This section is just a rubber connection tightened with screw fasteners so that I can open the skimmer here and replace the air stones when needed.
6: This bottom area is a plastic jug where the airstones are at.
7: This is just a cheap powerhead I used as a pump to push the water back in the tank(really had to cover the entire thing in epoxy because it kept leaking; Hopefully I don't ever have to replace it). I recommend a powerhead or very small pump since you don't want much water flow, and it uses very little power.
8: Another ball-valve to control the water output. The more closed it is, the higher the water level inside the skimmer becomes, which controls how high your foam can reach. Definitely needed IMO.
9: My tetra-tec deep water pump which you cant see in the pic.
10: The water then flows from the pump to the opposite end of my tank.
11: This is the collection area; There is a tube inside you cannot see where the foam spills over into this area; Make sure you can disassemble this part easily to clean it. Also, put an airhole at the top for the air to escape.
12: This is just an airtube with a valve on the end to drain the collection cup when needed.
Thats it. Let me know if you have anymore questions or need more closeups.

 

[darknes]

@HondoTech:
I don't have the link anymore. Do a search under my name and 'skimmer', and should be able to find it.

 

[iopusl]

dark, thanks for the info, much appreciated. sorry it took a little to get back to you; went down to the bahamas for a week.
Hondo, put " Skimmer Design 101 " into google. its the first one.

 

[darknes]

No problem.

 

[darknes]

@iopusl,
I just cleaned my skimmer, and decided I would show a few pics of what comes out of it. It holds about 3 cups of skimmate, but I didn't think about taking pics until I had the last cup left.

 

[darknes]

Closeup:

 

[iopusl]

damn dark, that's impressive. I'm almost there with mine just have to figure a way to increase water height in the tube.

 

[darknes]

If you are feeding your tube by a siphon, the water level won't go any higher than your tank water level.
I found that the siphon cannot keep up with the pump exactly, so the lower you have your pump output, the higher the level will be.

 

[iopusl]

thanks dark,
I ahve have the cup uncder the tank line. I was figuring how to keep the output of the skimmer slow enough so that it raise the water level in it with out flooding the display.
But I finally got that mofo.