Gravity Feed Downdraft Skimmer....

[TCUguy]

Here we go... do ya'll want to see if this will work? (BTW those who have been following I am ALMOST done with testing single LED's and their par... hang on in there).

I am going to make a gravity feed (from the overflow) downdraft skimmer. (using bioballs to break the air up). Question is... will it work?

1- I have two bulkheads on my new tank, one 3/4", and one 1". It is a "Herbie" style overflow, where the 3/4" will be under full suction (i.e. higer GPH and higher PSI). should be 300gph under full suction.
2- From the bulkhead to the bottom of my sump (where the skimmer will be) there will be 40" of completely vertical height... pretty far down to allow for proper water speed build-up IMO.
3- Air inlet will be the overflow itself, since the 3/4" inlet will be close to the surface and creating a "vortex" pulling down air into the tube while keeping full suction.

Basically, picture a etss or AquaC skimmer but being plummed from the overflow but without any air inlets (remember from the FULL SIPHON overflow).
[attachment=0]Skimmer.jpg[/attachment]

BTW I don't need this to be 100% efficient, and it is going on a small 40 gallon tank with A LOT more filtration (rather than solely relying on the skimmer itself). The purpose of this is to completely remove a second skimmer pump thus reducing operating costs, maintenance and noise.


Further readings in case you don't know what a downdraft skimmer is or what a herbie style overflow is.
http://w3page.com/fishline/gif/ddskimpz.jpg
http://www.nano-reef.com/forums/index.php?showtopic=69372&st=60

 

[Guest]

It won't work as down draft skimmer or venturi need pressure to shoot the water through the injector.

You can use overflow to feed an external skimmer instead of using a feed pump

If you want something cheap just do an air stone inside a cylinder with a collection cup
Sent from my iPhone using Tapatalk

 

[TCUguy]

@kuyatwo wrote:

Yeah I was thinking about the air stone as well... how about a mix?

Install an air inlet (powered by a small air pump) at the very top of the intake (by the overflow box)... this way the air mixes all the way down with the water and then gets broken up by the bio-balls in the skimmer... so half-airdriven and half-downdraft skimmer?

(pressure would be around 1.5psi btw at this height going into the skimmer).

 

[TCUguy]

I made some calculations and I actually think I might be able to use an Aqua-C Remora or EV series skimmer...

If you buy it it comes with a mj1200, rated at 295gph and 69" max pump height. This means that when installed on the skimmer it puts out 2.5psi and around 270gph.

I could do 1.5psi and the same GPH, or way more if I wanted to... so pretty close.

 

[Guest]

Yeah but the pump puts the pressure. If you block and overflow it just backs up is what I think will happen

 

[timthetoolman]

If you're getting the numbers from the .4331 psi per foot of elevation of water equaling 1.5 psi since it's 40" tall, I don't know if you would be able to get that if the bio balls were in the down tube. Pumps make pressure so they would have that available but when you restrict the flow of free flowing water I don't think it would work out the way you want. I don't want to keep you from trying it though. I made several different skimmers about 10 years ago using a venturi and noticed they were so inefficient that I had to have a lot of pressure for proper fractionation. Without the bio balls in the down tube I don't think you would get the contact time required to get the protein to stick to the bubbles though.
If you try it out post some pictures, I love this kind of stuff.
Good luck, Tim

 

[Guest]

might look at this design and maybe copy it

http://reefbuilders.com/2011/03/09/redline-hot1v2-protein-skimmer/#more-31244