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gbru316
08/31/2014, 12:37 PM
Why don't more people use countercurrent skimmers? They can be made for under $100 and can be far more efficient than most skimmers on the market today, with both decreased electricity cost and better skimming due to increased dwell time.

Is it the lack of desire to DIY? The lack of space for a tall skimmer? The associated expense (monthly replacement of airstone)?

wolfblue
08/31/2014, 04:03 PM
Before the haters show up, let me say I'm with you on this. I like air drive but I think they need to be taller than under the DT.

Now the $700 skimmer crowd should be along to tell you that retired NASA engineer's use super computers to design these 16" skimmers that hold ounces of water for a few seconds. And you cant build one that super duper efficient at home. They may however ask you to explain the term "dwell".

stancfii
08/31/2014, 04:33 PM
http://www.reefcentral.com/forums/showthread.php?t=2259680

ca1ore
08/31/2014, 04:45 PM
I think most people run their tanks off an in-stand sump which effectively eliminates a tall skimmer. If you are fortunate to have a basement for the sump, then tall is absolutely an option. My recirculating skimmer is about six feet tall - not airstone driven though, would never go back to those - and it works really well with counter current water flow and lots of dwell time. Very good performer.

gbru316
08/31/2014, 06:27 PM
Now the $700 skimmer crowd should be along to tell you that retired NASA engineer's use super computers to design these 16" skimmers that hold ounces of water for a few seconds. And you cant build one that super duper efficient at home. They may however ask you to explain the term "dwell".


Yeah. I guess I just don't "get" spending hundreds of dollars on a skimmer that doesn't perform as well as one that can be build for under $100. I mean, even if my display was in my living room, I'd find a way to incorporate a properly sized skimmer.

Maybe it's because I'm an engineer/DIYer, or maybe I'm just cheap :lmao:

Captivereef's skimmer design looks interesting. Might have to follow his lead when we move and have room for a large tank.

I can't tell from his drawing if the 1400 gph pump is an additional feed pump or recirc. I might be tempted to utilize the venturi on a recirc pump, pulling water from the top of the skimmer and injecting it in the bottom, thus vastly increasing contact time, since contact time is the name of the game. Hell, according to Escobal's book, some proteins take a full 2 minutes to bind.

smmiller506
08/31/2014, 06:40 PM
My recirculating skimmer is about six feet tall - not airstone driven though, would never go back to those...

Would you mind describing how your skimmer is set up? Or what you used for reference? Thanks!

nikon187
08/31/2014, 06:49 PM
Before the haters show up, let me say I'm with you on this. I like air drive but I think they need to be taller than under the DT.

Now the $700 skimmer crowd should be along to tell you that retired NASA engineer's use super computers to design these 16" skimmers that hold ounces of water for a few seconds. And you cant build one that super duper efficient at home. They may however ask you to explain the term "dwell".

16 inches tall and ounces of water..lol. try 3.7 gallons of water in this bad boy. And nasty black sludge all day long. Counter current certainly work well but ill never go airstone ever again



http://i281.photobucket.com/albums/kk206/nikon1879/c7624f73-f7a6-44a2-a962-1e31a1f58a13.jpg (http://s281.photobucket.com/user/nikon1879/media/c7624f73-f7a6-44a2-a962-1e31a1f58a13.jpg.html)

gbru316
08/31/2014, 06:56 PM
16 inches tall and ounces of water..lol. try 3.7 gallons of water in this bad boy. And nasty black sludge all day long. Counter current certainly work well but ill never go airstone ever again



http://i281.photobucket.com/albums/kk206/nikon1879/c7624f73-f7a6-44a2-a962-1e31a1f58a13.jpg (http://s281.photobucket.com/user/nikon1879/media/c7624f73-f7a6-44a2-a962-1e31a1f58a13.jpg.html)

What's your flow rate through the skimmer? It CAN be done on a shorter skimmer, but flow rate needs to be drastically reduced.

My planned skimmer for my 10g will be about 2' tall with a flow rate of less than 3 gph.

http://www.hawkfish.org/snailman/images/skimdesign/skimme1.jpg

http://www.hawkfish.org/snailman/images/skimdesign/sizing.gif

Snailman's skimmer design 101 (http://www.hawkfish.org/snailman/skimmer101.htm)

sirreal63
08/31/2014, 07:18 PM
Counter current does not mean air stone driven. My recirc Vertex is counter current, and being a recirc, I have complete control over air draw and flow through. I had my days with air stones, not something I want to go back to. They work great, but not exponentially better unless they are tall. I get more than adequate performance from my IN-180 body and since I don't have the space for a 6' tall skimmer, it is a moot point. If I had the room, I might consider it, but without wooden air stones.

gbru316
08/31/2014, 07:19 PM
Yeah, didn't mean to imply that countercurrent = airstone.

sirreal63
08/31/2014, 07:24 PM
No problem, just thought it needed clarification for those who havent been around very long.

The guy who got me into corals had a nice 6' tall home made version with an Alita pump, and though it worked well, it didn't really do any better than my recirc G3. Our system volume and bio-load was close to the same and I am sure if had traded skimmers the results still would have been about the same.

ca1ore
08/31/2014, 07:43 PM
Would you mind describing how your skimmer is set up? Or what you used for reference? Thanks!

Mine is not a DIY skimmer. It is a MTC recirculating, counter current model (cost about $700 too; but that includes the pump and some really nice rubber feet :lol:) ......

http://i1361.photobucket.com/albums/r680/ca1ore/IMG_0862_zpsb02719ca.jpg (http://s1361.photobucket.com/user/ca1ore/media/IMG_0862_zpsb02719ca.jpg.html)

I'm long past the point in my life when I have the time to attempt to make one frankly. If I was 25 ......

Body tube is 48", base about 8" and neck/head about 18".

vpaul79
08/31/2014, 08:20 PM
As an owner of a $700 skimmer, I'm going to plead ignorance. Can someone explain the pros and cons of a counterflow skimmer compared to the traditional compact skimmer?

sirreal63
08/31/2014, 08:34 PM
Follow the link in post #8. In basic terms, as the bubbles rise, they interact with the flow of raw water entering the skimmer so that the downward flow from the raw water meets the rising bubbles.

Reefvet
08/31/2014, 08:38 PM
Yeah. I guess I just don't "get" spending hundreds of dollars on a skimmer that doesn't perform as well as one that can be build for under $100.

Since you've clearly never owned one how would you now how well a skimmer costing hundreds of dollars works ?

ksed
08/31/2014, 08:42 PM
No problem, just thought it needed clarification for those who havent been around very long.

The guy who got me into corals had a nice 6' tall home made version with an Alita pump, and though it worked well, it didn't really do any better than my recirc G3. Our system volume and bio-load was close to the same and I am sure if had traded skimmers the results still would have been about tthe same.
Jack

With the 6 ft. skimmer most likely having more contact time than your skimmer. I am assuming you feel the added contact time doesn't have much benefit from your experience

ca1ore
08/31/2014, 08:52 PM
How the $700 skimmer crowd should be along to tell you that retired NASA engineer's use super computers to design these 16" skimmers that hold ounces of water for a few seconds. And you cant build one that super duper efficient at home. They may however ask you to explain the term "dwell".

Ah, the cynicism of inexperience! I've argued many times that the in-sump skimmer is perhaps the most overpriced item on today's reef tank menu, and I look at many of the recent supposed 'innovations' with a jaundiced eye; however, just saying one can DiY a skimmer at home and have it be more efficient than a commercial model doesn't makes it so. And really, how would you know beyond just thinking it must be so. I built my first three skimmers and they worked fine (they even used wooden airstones, ugh) but my first commercially purchased unit was far better (an early MTC HSA 1000). Maybe there's more 'art' to skimmer design than 'science' and maybe folks with time on their hands actually can make a competitive model ..... maybe!

sirreal63
08/31/2014, 08:55 PM
I believe in contact time, it works, if the air/water balance is there, and that is where it is hard for tall air stone skimmers, getting enough volume of air. For the venturi driven tall skimmer this is not as hard, driving enough air through air stones requires a strong pump, my friend tried several before he went with a down draft skimmer. Too strong of a pump and even with an limewood stone, the bubbles can get large. I would never go back to wooden air stones, but there are some new ones I have seen that seem to have a great advantage over wood in creating very fine bubbles even when under high air volumes.

My ideal,skimmer would be like Ca1ore's, Venturi driven but I would probably go with a tall LifeReef.

gbru316
08/31/2014, 09:18 PM
Since you've clearly never owned one how would you now how well a skimmer costing hundreds of dollars works ?
Au contraire. I've been in this hobby off and on for almost 15 years. I'be had many skimmers.

ksed
08/31/2014, 09:28 PM
Jack
I was under the impression that with airstone driven skimmers the amount of air injection is endless, within reason that is. But limitation would be the air pump but even at that there are quite a few pumps that have more out put than you would ever need. Then air stones you can add as many or as big as you want. Yes they are a PITA to maintain. But the amount of air input they can rival some very large venturi.

gbru316
08/31/2014, 09:29 PM
I was under the impression that with airstone driven skimmers the amount of air injection is endless, within reason that is. But limitation would be the air pump but even at that there are quite a few pumps that have more out put than you would ever need. Then air stones you can add as many or as big as you want. Yes they are a PITA to maintain. But the amount of air input they can rival some very large venturi.
There actually is a limit/ideal volume of air per total skimmer volume, regardless of air source. The calculation is in the link I posted.

ksed
08/31/2014, 09:34 PM
There actually is a limit/ideal volume of air per total skimmer volume, regardless of air source. The calculation is in the link I posted.

Yes! This is understood.

slief
08/31/2014, 10:08 PM
Au contraire. I've been in this hobby off and on for almost 15 years. I'be had many skimmers.
15 years or 5 to 7?
:reading:

http://i390.photobucket.com/albums/oo347/shleif/imagejpg1_zpsd81aefa7.jpg

ca1ore
08/31/2014, 10:10 PM
Hey, don't go and cloud the issue with facts ..... I suppose in geological terms, 5 years could be considered to be 'almost 15'. Very funny?

gbru316
08/31/2014, 10:10 PM
I started working at That fish Place around 1999 in the fish room. Really hate how argumentative and childish this place can be sometimes.

Reefvet
08/31/2014, 10:15 PM
Au contraire. I've been in this hobby off and on for almost 15 years. I'be had many skimmers.

Well I've got you beat there. I've been in the hobby for 40+ years. I've built counter-current air driven skimmers but that was nearly 20 years ago. I had to special order the large diameter clear acrylic and spent days building them. They worked and they worked well but they pail in comparison to today's cone designs.

I have an Aquamax ConeS 1 and a Vertex Omega 150. I got them used, like new, for a couple hundred bucks apiece. They're both dead silent and amazingly powerful skimmers. They're set and forget, air driven never is.

Now if you enjoy building one that's another story but don't kid yourself. You'll never make anything as powerful as a cone, needle-wheel skimmer for $100. Even if your time is worth very little.

slief
08/31/2014, 10:32 PM
I started working at That fish Place around 1999 in the fish room. Really hate how argumentative and childish this place can be sometimes.

When you first started this thread and made the $700 club remark, I couldn't help but wonder what your experience level was to make such a statement. I checked your profile and took note and kept my mouth shut until you followed up with 15 years experience which confused me based on your profile.

After 27 or so years of never being without a large salt water tank (or 3), I resemble that remark. I'm in that $700 plus club for what I believe are good reasons. Especially after owning pretty much every conceivable skimmer design out there to compare to. I've owned dozens, including home made, my share of stone driven ones, counter current, beckett, venturi, down draft, mezzei injected ones, Klase etc.

What I've learned is that there are many ways to skin a cat. It doesn't mean that even the cheapest solutions don't don't skim. It just that there are better more efficient solutions that do so with less power consumption, more efficiency, in less space and much less maintenance. And yes, some if not all of those solutions may come with what you consider a heavy price tag. In the case of a large tank like mine, the cost can be significant compared to a 10 gallon tank so a blanket $700 club statement really makes no sense.

If I had a 10 gallon tank, $100 would seem like a lot compared to a 600+ gallon heavily stocked reef system where $700 is usually only a starting for a good, new or newer non DIY, proven solution that will not only make some nasty skim but will also increase ORP by sheer virtue of the amount of dissolved O2 that it puts into the water while requiring very little maintenance.

sirreal63
09/01/2014, 06:31 AM
Jack
I was under the impression that with airstone driven skimmers the amount of air injection is endless, within reason that is. But limitation would be the air pump but even at that there are quite a few pumps that have more out put than you would ever need. Then air stones you can add as many or as big as you want. Yes they are a PITA to maintain. But the amount of air input they can rival some very large venturi.

For the most part that is correct, however, the more air you push through one, the larger the bubbles will become. To keep the bubbles small, you need more air stones, and there is a limit to how many you can run efficiently. Air, like water, will take the path of least resistance, so keeping the air volume equally distributed becomes an issue as you add more lime wood.

wolfblue
09/01/2014, 11:09 AM
I knew this was going to be a good one! Nothing wrong with arguing gbru316. So far just people trying to help out with the experiences they have. And I was the one who said "air drive" and "$700". I have a $700 skimmer sitting on the ground here. Its nice and you could CC air drive or venturi or needle wheel the thing. It just does not look like its worth $700 and I know I could built two with pumps that work as good or better for that price. But it does set me off a little when people say you cant build one that works at home.

Ah, the cynicism of inexperience! Hey! I thought we were on the same side. And to think I was about to leave my wife and come live in your basement. Not to say I would rather look at the stuff in your basement than look at her. I'll get a job at Mystic you know, so I can chip in. And you'll have a pro life support operator down there in case a pump sounds funny.

Still not sure if you meant me but I started freshwater in 1972 and I do have some experience with salt. I had to build my first skimmer because they weren't selling them yet. We had a dozen LFS back then and nobody could even order one. Not even in TFH or Aquarium magazine. So I built one of those German tube bubble things and was amazed. And my experience goes back to walking out in the ocean at Pennekamp with a cooler to pick up rocks and buying TL 03 lamps at the commercial lighting distributor. All they had was daylights at the LFS and no live rock. My first 5500K MH and giant hot buzzing ballast came from the light store too.

I did 20 years of drainage and roadway design so I can calculate gravity flow. Then I quite that to do aquarium maintenance and added pressure flow. They hired me because I was a very advanced hobbyist. Some advanced hobbyist's would have 600 gallons total system. Now I have a protein skimmer that holds 600 gallons and I just put about $80K in ozone stuff for one system. They are clueless what I do here but they can see the results. Now I have a reputation so I get calls for help on problems from all over the country.

So I got some experience but I'm still learning. Learning here from smart people that sometimes get argumentative buts that's just the passion they have for this. Now they are trying to talk me out of this 30 year wood airstone thing and they might do it. Until the ceramic stone people show up and convince me to buy one for a try.

I have learned today that if a skimmer makes black stuff it is a good and probably highly technical design. But that 600 gallon one up there never gets much past off-white foam. Sometimes tan but never brown or black. Does that mean its a bad design? Could not be a bad design, it cost $12k without ozone. I must have it adjusted wrong. Sorry, not a chance.

It is just slightly on the wet side but that's how I like it. And for me a bubble that does not want to pop needs to go away. Condensing it down to black stuff might be necessary on some systems but I think you'll be letting stuff get past the skimmer that you could stop there. Not optimum for me but 70% of that stuff gets past the skimmer anyway. What's the difference between stopping 24% of that stuff and 26%? Not $500 worth. So even if my PVC skimmer is not as good as your modern mini miracle its still good enough. But mine is as good because I got size to make up the difference.

And a quick thing about air drive for those following along. A home made skimmer could be cheaper but the air pump will cost $200-$300. That's more than a venturi pump.

wolfblue
09/01/2014, 11:36 AM
16 inches tall and ounces of water..lol. try 3.7 gallons of water in this bad boy. And nasty black sludge all day long. Counter current certainly work well but ill never go airstone ever again


First...custom 84 x 24 x 24. 24"x24" is the perfect zone and 84" must be pretty sweet. Nice choice and nice fat skimmer but it doesn't look that big. Looks 6" wide if that's 1/4" glass with 1" PVC back there. But it must be 9" wide with the main body 13" tall to get 3.7 gallons which is pretty good.

I want 1x per hour so say 240 GPH. And I would say 10% of the volume is air and I want two minute dwell. So my homemade skimmer behind the wall starts at 10.5 gallons for that. But you can get one on Craigslist for the same price and put it under cabinet. Though you cant very easily put another 100 gallons under the cabinet.

ca1ore
09/01/2014, 12:07 PM
Hey! I thought we were on the same side. And to think I was about to leave my wife and come live in your basement. Not to say I would rather look at the stuff in your basement than look at her. I'll get a job at Mystic you know, so I can chip in. And you'll have a pro life support operator down there in case a pump sounds funny.

Oh dear, intended to type 'ah, the cynicism of experience' which I'd view as a complement :)..... Cynicism of inexperience makes no sense ...... Small screens, fat fingers and auto-correct are the scourges of my existence .....

ca1ore
09/01/2014, 04:54 PM
I have had a couple of people ask .....

My MTC skimmer is not a 'stock' unit as I had them make me an extended body tube. I also bought the base unit second hand, though very well cared for, so my total 'investment ' is somewhat less than if I had bought it new.

nikon187
09/01/2014, 06:32 PM
[QUOTE=wolfblue;23064232]First...custom 84 x 24 x 24. 24"x24" is the perfect zone and 84" must be pretty sweet. Nice choice and nice fat skimmer but it doesn't look that big. Looks 6" wide if that's 1/4" glass with 1" PVC back there. But it must be 9" wide with the main body 13" tall to get 3.7 gallons which is pretty good.

Skimmer is in my sig swc 250 so 10 inch body 5.5 inch neck 24 ish inches tall.


bubble blaster 5000 ( 450ish gph and 2100lph of air ) 55w

footprint is 14 x 17