Any experiences/opinions on these DIY educators?

[Edward Smith]

http://cgi.ebay.com/Mega-Flow-eductor-nozzle-increase-flow-2-3X_W0QQitemZ300123675001QQihZ020QQcategoryZ46312QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[CyclistMT]

Yes, build them yourself for $5 each. Here's the thread to get you started.

DIY Eductors (http://www.reefcentral.com/forums/showthread.php?s=&threadid=1099596)

I guess you can try to sell anything on e-bay.

Good luck Edward.

[Edward Smith]

$5 for one that "kinda works" and.....

-one hour at HD wandering around because I don't know where anything is and I have attention deficient.

-no sex for a week because I'm became frustrated making it work and yelled at my wife.

-one trip to the ER (meeting my $300 insurance deductible) for a few stitches because some of us shouldn't be playing with sharp objects or power tools.

or

Hmmmm.......$15 for one that actually works and delivered to the door.


Just kidding :rollface:

Considering I'll need four of these, I might as well make them myself.

Thanks

[Blackacid]

If you don't have the drill bits that can raise your price a bit more. Makes sense if you're planning to build more than one of these but if you only needed one... Then you're probably better off just buying a manufactured version from Premium Aquatics or other seller.

As for the ebay listing.... Wow. Maybe I should buy just the parts and sell them as "kits" on ebay. :lol

[RocketEngineer]

Considering you can buy an engineered model that should work considerably better then the DIY version for $30, personally I would rather buy the real deal and know that it will work exactly as intended.

[BeanAnimal]

Exactly...

the engineered design will far outperform the DIY stuff and will do so for just a few bucks more.

[Daemonfly]

Funny how that looks exactly like one of the ones from a thread around here.


Either way, I've seen better DIY ones that take less parts.

[RichConley]

Are we assuming that Penductors are "engineered" again? I'm pretty sure that was thoroughly debunked.

[BigJPDC]

yeah, I've seen better ones too.

:rollface:

[BeanAnimal]

<a href=showthread.php?s=&postid=10209643#post10209643 target=_blank>Originally posted</a> by RichConley
Are we assuming that Penductors are "engineered" again? I'm pretty sure that was thoroughly debunked.

I don't remember it being debunked... I remember several very uninformed people not understanding the basic principle and instead arguing that such "science" was nonsense.

Those are the same people that are convinced that any joe can bend a reflector that will perform as good as any other reflector.

Rich, the bottom line is that the penductor is a well designed device that has a generally good shape. It is fabricated with smooth transitions and is modeled to operate in the general pressure and volume for the same size pumps we are using on the hobby.

It is certainly NOT engineered perfectly for YOUR pump or HIS pump, but again it is still MORE refined than what the average Schmoe is going to cobble out of PVC fittings. It likely moves MORE fluid than anything any of us are going to build using the same size constraints and aesthetics.

The nonsense that several people have used to measure the flow of these (filling baggies?) and the like is exactly that NONSENSE.

[RichConley]

<a href=showthread.php?s=&postid=10214008#post10214008 target=_blank>Originally posted</a> by BeanAnimal
I don't remember it being debunked... I remember several very uninformed people not understanding the basic principle and instead arguing that such "science" was nonsense.

Those are the same people that are convinced that any joe can bend a reflector that will perform as good as any other reflector.

Rich, the bottom line is that the penductor is a well designed device that has a generally good shape. It is fabricated with smooth transitions and is modeled to operate in the general pressure and volume for the same size pumps we are using on the hobby.

It is certainly NOT engineered perfectly for YOUR pump or HIS pump, but again it is still MORE refined than what the average Schmoe is going to cobble out of PVC fittings. It likely moves MORE fluid than anything any of us are going to build using the same size constraints and aesthetics.

The nonsense that several people have used to measure the flow of these (filling baggies?) and the like is exactly that NONSENSE.


Bean, again, do you have any evidence that the Penductor is an engineered piece of equipment, and not just the same crap these companies throw out all the time.


" It is fabricated with smooth transitions and is modeled to operate in the general pressure and volume for the same size pumps we are using on the hobby"

Thats a HUGE assumption Bean. The same sort of assumption I've been burned making, numerous times in this hobby. It is my oppinion, that in general, for aquarium use, things aren't modeledat any point. Theyre cobbled together.


I'm not arguing with you about Eductors in general, but the pieces of junk they are selling to aquarists.


Look at skimmers...and tell me that all the skimmers out there being sold to aquarists were designed and modeled by people who understand the principles at work. Its clear thats not the case. Look at reflectors. Same deal. I see no reason to think that the Penguin-Eductor is any better.

[BeanAnimal]

The Penductors are not aquarium equipment... they are low cost industrial mixing eductors (sparging devices) that are used to mix fluids. They are being SOLD as hobby equipment because there is a small niche market.

This is different than a knock off product being manufactured and sold as something that it is not...

A simple LOOK at the devices is evidence that they are fairly well shaped. The smooth transistions and basic design shape are exactly what the DIY units DO NOT have.

[Randall_James]

Guess I have to agree with BA this time, we had to purchase eductors for a mixing tank and there is absolutely a difference in an engineered eductor .

The ones we ended up buying were $115 each vs $30 for the ones that could not do the job. (this was a commercial mixing tank for mixing soda ash for ph treatment in a water treatment plant). Both units made very similar claims for water movement ratios but they had no where near the same performance.

[Shark Keeper]

Well I built one of the DIY's last year and it work great. It is very simple and took less then a half hour to make (including the trip to HD). I have not had one single problem out of it and it has doubled if not tripled my output from my panworld pump.

It was really worth the effort to me since I like to try different DIY projects and had nothing to do with the cost savings.

[Blackacid]

If it works to the builders satisfaction then what is the problem? If you don't like how it looks or can't be bothered with spending 30-45minutes building one... Don't. Why does it have to be a big debate?

[Randall_James]

Not a thing wrong with a DIY unit IMO.

Most of the commercial units we worked with had around a 4-1 ratio at 5psi. But it takes the flow between 8-10' to disperse (sort of long for most tanks)

That would make me think that cheaper or DIY might be more appropriate for home tanks that are 4-6' long

[RichConley]

<a href=showthread.php?s=&postid=10214268#post10214268 target=_blank>Originally posted</a> by BeanAnimal
The Penductors are not aquarium equipment... they are low cost industrial mixing eductors (sparging devices) that are used to mix fluids. They are being SOLD as hobby equipment because there is a small niche market.

This is different than a knock off product being manufactured and sold as something that it is not...

A simple LOOK at the devices is evidence that they are fairly well shaped. The smooth transistions and basic design shape are exactly what the DIY units DO NOT have.

Bean, plenty of the DIY eductors have the smooth transitions and basic shape.

Its the modeling and theory that they dont have. I'm arguing that neither does the penguin. Even if it has been modeled, without being matched to the pump, it may not be better than DIY.

[BeanAnimal]

<a href=showthread.php?s=&postid=10216564#post10216564 target=_blank>Originally posted</a> by Blackacid
If it works to the builders satisfaction then what is the problem? If you don't like how it looks or can't be bothered with spending 30-45minutes building one... Don't. Why does it have to be a big debate?

Why do comments like this CONSTANTLY show up any time somebody comments on a design or an idea.

Lets make this clear. SOME PEOPLE like to absorb as much information about a subject as possible. Sometimes that measn discussion of ideas and rejection of otherws. Do YOU have a problem with the added conversation? It sure sounds like it.

It is a big debate becuase of comments similar to those that you just made.

The idea here is to further knowledge by trading information. Some of us may have more knowledge than others. Please don't make this into one of those "stop bashing people" threads, nobody is bashing anybody.


Randall, you are saying that the stream close to the more efficient eductor is too powerfull and you would rather have a wider dispersion area for the same general flow?

The flow multiplication of the eductor is a function of it's shape and the velocity of the stream being forced through it. Somewhere in my stack of PDFs I have a very good design paper regarding fluid eduction. I may have posted it in an old thread and will look for it.

[BeanAnimal]

Bean, plenty of the DIY eductors have the smooth transitions and basic shape.

I would fully disagree. Most are very crude copies that barely resemble the classic venturi shape that is SO IMPORTANT to the operation. I have seen very few DIY eductors that even come close to being the correct shape for efficient operation.

A simple HOOP around a nozzle will act as an eductor (we use them on water cannons to keep dust down by drawing air in with the sprays). They get the job done but are certainly not optimized in any way.

That said:

As others have mentioned... if the (any) DIY unit moves enough water to make the creator happy... well then, ALL is good. The comments and discussion are aimed at the principles and reality of operation, not the satisfaction or achievment of the DIYer.

Too many technical concepts get glossed over in these forums and I fear that many people are done a disservice by being led to believe that it is easy to build a better mousetrap when in fact it is very hard to even build an equivalent one.

Most folks understand that you don't DIY eyeglasses or camera lenses, but just can't understand why you don't DIY reflectors. :)