DIY Venturi Air Pump from EcoPlus 396 Water Pump

[motta-tokka]

DIY Venturi Air Pump from Ecoplus 396 Pump

Imagine the possibilities of directly injecting air into your solutions this way. We are talking the feed portion to your plants. Enjoy

http://www.youtube.com/watch?v=6Ka9uMNgX9U

 

[Lost]

Its a great idea actually.Inject the air just before the feed so you get a crazy venturi. I would actually hook an air line to it to give it more oomph

 

[mrdizzle]

i love the venturi method, I have them in every res

 

[Seamaiden]

Um, before you install a real venturi you might want to learn what making a venturi does, what foam fractionation is and then stop and consider--do you really want to filter out any of the things you've just put in?

LMFAO! He's telling you how to use the powerhead in one manner for which it was designed??? Oh man, this is priceless. Where's the facepalm smilie?

There's a problem with that thing if it's buzzing like that, a powerhead should be completely silent. Maybe the video camera is picking up EMF from the impeller assembly (again, a problem, these things are designed to be used in the home). In any event, what he's saying isn't entirely correct.

He hasn't created a true venturi, again, something wrong with the pump if he's got the tubing hooked up correctly and it's making large bubbles. All powerheads are made to easily create a venturi by adding a bit of airline to the hole up over the outlet (or, at least they were when I worked retail). Then there's the additional issue of this--if you really achieve the microbubbles that are produced by a true (and truly effective) venturi flow, you will get a nice, thick, dry foam. This is the chemical filtration aspect of using a venturi to make a better protein skimmer (aka foam fractionator).

Foam fractionators--love 'em. The bigger the better.

http://en.wikipedia.org/wiki/Foam_fractionation

Foam fractionation is a chemical process in which hydrophobic molecules are preferentially separated from a liquid solution using rising columns of foam. It is commonly used, albeit on a small scale, for the removal of organic waste from aquaria; these units are known as 'protein skimmers'. However it has much broader application in the chemical process industry and can be used for the removal of surface active contaminants from waste water streams in addition to the enrichment of bio-products.

Here's a good video showing very well a good venturi (it's injected into the water column long before the water enters the fractionation chamber, thusly making for a maximum venturi effect in the movement from higher to lower pressure). Watch especially starting at :25, how the foam created moves up the column, becomes denser and denser, indicating more water is being removed and a purer product is achieved. This is desirable in many applications, but to me it's not desirable when you're trying to keep nutrients dissolved, as those qualify chemically as DOCs (dissolved organic compounds).

[youtube]aCStES91WhY[/youtube]

Want to seriously increase the dissolved O2 levels in your water column? Create something with a lot of 'riffles', like a waterfall. For instance, I've seen where one guy coiled corrugated flexible piping (I think it was split on one side so he put that side up) and pumped the water at a low rate through the coils. Or, look at something like a trickle filter.

 

[mrdizzle]

I dont even know what to say to that ^^^ is that what you use, a protein skimmer?

perhaps the fact he was using a 2gal bucket didnt show the full effect of what drawing air in through a 1/4in tube and sending into your res does

 

[Seamaiden]

On my valuable aquaria, yes, I might be using a protein skimmer. Much, much more likely for *me* would be to use a refugium. Low flow with a high water volume and surface area, utilizing live rock and macroalgae to perform their natural functions which equals to fantastic, NATURAL filtration for my tank. That's probably because I helped with a book that was focused on the natural marine aquarium and it really got me into that kind of technology.

The reason why some aquarists like skimmers is that they are very efficient at removing many compounds that very quickly add up to high nitrate levels as they decompose. This is especially important if you're keeping miniature reef with a focus on inverts.

Bubbles of the type you have pictured there don't have enough surface area and are not present in high enough density to really have much effect on DO levels. It's the surface agitation that's being created by both the bubbles and the powerhead's effect on water movement that is having the greatest effect. And surface area-to-volume, that's also a factor.

All I'm saying, really though is this--IF you create a very functional venturi, you're going to start a true chemical filtration process that will likely remove some of the very compounds you've just put into the reservoir. Ok, maybe that's not all I'm saying, I figured that I'd do "my thing" and not just point out what I see wrong with something, but try to present a solution or alternative. The other point was that all powerheads are made to do what this guy is putting out as a "DIY", which is laughable.

 

[mrdizzle]

I dunno seems like pumping a steady stream of air into your res isnt a real waste of the 40watts and $20 it cost, I dont own a DO meter so I could be wasting my time I dont know but I dont see how I could apply the zeroDC protein skimmer into my hydroponic system

 

[Seamaiden]

You're not picking up what I'm putting down here.

I'm not saying to buy the ZeroDOC skimmer for your reservoir, in fact I'm saying that it makes no sense to remove (via foam fractionation, ie venturi, which in my mind = superfine bubbles) what you've just put in. I added that video to show how a good venturi works and, most importantly, what will happen if it's working well. That foam that builds up at the top could be all the nutrients you just put into your res, do you want to remove them?

I'm also saying that you can achieve good DO levels just by creating sufficient surface turbulence/agitation, and that's what air bubbles of the size you and the fellow in the original video are creating can do. The exchange does not happen "at" the bubble itself.

If you point that pump outlet up toward the surface and make it roil and turbulent, you'll be achieving the exact same thing as you are with pushing bubbles through it. If you pump water through something like a trickle filter or the corrugated pipe I mentioned above, you will achieve maximum O2 saturation possible for that particular body of water, dependent of course upon a few factors--temperature, saturation of other compounds, what those compounds are.

I'm also saying that it's effing hilarious that this guy is making his "trick" out to be some DIY deal when the pumps are designed to include this feature. A feature I personally hate seeing people use in their aquaria because if you do get the superfine bubbles you can give your fish a form of the bends. Plus your tank looks like you filled it with fizzy water.

Ya dig?

 

[motta-tokka]

This is a basic venturi that people have done in a million different ways. Most ways require a ton of fiddling with fittings to get the water/air/flow mixture correct, which is a pain if you have tried it.

google basic venturi and look and the images.