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Nick, the facts that I see posted are opinions, not facts. There is nothing that proves dwell time is the most important factor in skimming. There is nothing that suggests there is a 85% water to 15% air ratio. I would totally disagree with that theory. There are no facts that prove more air is the most important factor in skimming, nor are there facts that suggest NW, beckett, venturi, air driven are better. The talk of different types of molecules bonding at different dwell times is great info, but are those molecules good to extract? And to say that clear skimmate is the best is rather hard to swallow. And i'm not trying to put Mike down at all as I love talking about this stuff, especially friendly talk : ) I just haven't ever seen a skimmer produce like a beckett besides these high air skimmers that are very efficient in energy.
 
Nick: Not to be argumentative, but personally I do not see the math that Mike has posted as "fact", but anecdotal as well, and outdated to some extent. IMO, there is more anecdotal evidence to support the "high air, short and wide, single pass" skimmer philosophy than there is anecdotal evidence to support the math that Mike has proposed.

The sad reality is: There is no one that can even determine exactly "what" we are removing by skimming. There is no means to test the "what's". There is no repeatable and verifiable way to even test a skimmers performance against another OTHER than anecdotal evidence. There are a few institutions working on some ways to test skimmers, but even they have not come up with a test agent(s) that they can put in the water and then test in the skimate that will accurately represent both hydrophylic and hydrophobic DOC's of varying degree's of attraction/repulsion to the air/water interface. Hopefully some wiz-kid reef geek will come up with something that CAN be accurately and repeatably be tested and verified :D
 
Mike, Marc, Luke and Nick...thanks for allowing me into your conversation! It seems like there are a few minds here that know skimmers...Maybe WE can actually accomplish something here :lol:
 
Na I doubt we'll accomplish anything more than a fun argument! lol

And thats the prob with skimming, there's not really any proof that this is better than that. Only opinions. I do think that a skimmate a bit on the wet side is better than the dry side, as i can see proof in my tank. And if it smells like sewage, its pry best to be out of my tank : )
 
Nick, the facts that I see posted are opinions, not facts. There is nothing that proves dwell time is the most important factor in skimming. There is nothing that suggests there is a 85% water to 15% air ratio. I would totally disagree with that theory. There are no facts that prove more air is the most important factor in skimming, nor are there facts that suggest NW, beckett, venturi, air driven are better. The talk of different types of molecules bonding at different dwell times is great info, but are those molecules good to extract? And to say that clear skimmate is the best is rather hard to swallow. And i'm not trying to put Mike down at all as I love talking about this stuff, especially friendly talk : ) I just haven't ever seen a skimmer produce like a beckett besides these high air skimmers that are very efficient in energy.

Luke re-read what I posted. I'm the one that said dwell time was one of the most important factors...not Mike. My point was that Mike is making statements regarding flow through rates, dwell time, and bombardment rates that can be proven or disproven. You are stating that "I've ran very long dwell times in recirc's and to be honest i've had much better luck with single pass skimmers pulling tons of air." Those type of statements are anecdotal and cant be proven.
For sake of of arguement, what do feel are the most important aspects of skimming and why?

(For the record, this was Mike's overall goal in stirring the pot like this...He loves to get things going and then sit back and watch....:lol:)


Nick
 
AMEN :lol:

Well to be honest I have taken many of Mojo's "Ideas" and used them in my own way they proved out everytime. The cone is so limited in use that direct relationship to what you are saying is a mute point. You and your minions of thought may have the skimmer and there will always be the old "my Dad is better then your Dad" syndrom. Its biased as is ours. So to say who is right is dependent on where you are standing. Obama or McCain, Frick or frack. Its relevant to who expierences it. You may prove out and your opinions becoame fact, but until that time no need to call Einstein outdated, his theories are still relevant today as is Mojo's.
 
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I dont want this to appear that I'm "sticking up" for Mike.

1...he doesnt need me to.
2....its not what I'm doing.

Honestly, I dont know enough about skimmers to really do more than follow along and try to understand the why's and wherefores....I'm picking up just as much from all of this as you guys are.

Nick
 
I am not sticking up for Mojo as well, But until there is enough evidence saying it is so, then I have to stick up for whoever gave me the info I know works.
 
If what you guys are stating is true about dwell time being the most important factor, then are all the manufacures incorrect in there new designs? Why would everyone be moving to more air and better transition of the foam? Its not a huge argument these days. A taller skimmer use to be the best but it seems the shorter, less wattage, better transition skimmers seem to be the best out there. If taller and 85% water 15% air skimmers were the wave of the future, then BK, ATI, SWC, ER, CV, Vertex, Bermuda, ATB, Deltec must have it all wrong..... Did i miss anyone? Or is top fathom still king these days : )
 
Well to be honest I have taken many of Mojo's "Ideas" and used them in my own way they proved out everytime. The cone is so limited in use that direct relationship to what you are saying is a mute point. You and your minions of thought may have the skimmer and there will always be the old "my Dad is better then your Dad" syndrom. Its biased as is ours. So to say who is right is dependent on where you are standing. Obama or McCain, Frick or frack. Its relevant to who expierences it. You may prove out and your opinions becoame fact, but until that time no need to call Einstein outdated, his theories are still relevant today as is Mojo's.


...I was merely "amen"ing lukes statement of "...And if it smells like sewage, its pry best to be out of my tank :)", which I might steal as a quote for my sig :lol:

Although, To me this discussion has digressed away from cones into a discussion on the benefits and downsides of the 2 skimmer designs being discussed...basically, the "tall and skinny' skimmer, and the "short and fat" skimmer. I'm just curious if the same results can be attained using Mike's math vs. Luke and I's "brute force" type skimmer.
 
In the end, what really matters, anecdotal or not, is the state of the fish and corals that we are all keeping...so, whatever gets the job done!

I'm in the same boat as Luke though...My wife DOES NOT want a 6' tall skimmer sitting in the living room ;)
 
Nick, the facts that I see posted are opinions, not facts. There is nothing that proves dwell time is the most important factor in skimming. There is nothing that suggests there is a 85% water to 15% air ratio. I would totally disagree with that theory. There are no facts that prove more air is the most important factor in skimming, nor are there facts that suggest NW, beckett, venturi, air driven are better. The talk of different types of molecules bonding at different dwell times is great info, but are those molecules good to extract? And to say that clear skimmate is the best is rather hard to swallow. And i'm not trying to put Mike down at all as I love talking about this stuff, especially friendly talk : ) I just haven't ever seen a skimmer produce like a beckett besides these high air skimmers that are very efficient in energy.

Actually there is a whole world of documented Facts & studies on fractionation, the most of it is proprietary & not accessible to the public, it is a science studied very heavily in the oil industry, separation & fractionation is part of the processes used in petrochemical industry & almost all of it is proprietary because it is a business & world of competition but the information is there & these separators & skimmers are designed accordingly. Where do you think skimming came from, we've been doing it for over a 100 years. :)
I know there is more to it by design depending on what your separating & separating is all what we're doing here. Ive personally seen designs to do just as Mike mentioned but lets say on a skimmer that is 40ft long & maybe 8ft round or maybe 60ft tall & 6ft round, made of steel & you would have no idea what in the hell it was if you looked dead at it LOL.
Companies in our hobby produces products to fit our needs & demands, making a smaller footprint skimmer is more desirable by many & part reason why they continually work on new designs to make them better.
IMO & only my Opinion, the smaller cones can make-up for some of the performance lost due to height & size because of their design but in reality the ideal design was made many years ago but the practicability of having it is way outdated because most of us want plug in play, I know I do & I don't want a big skimmer for a small tank & for that cost goes up for a better design for a smaller skimmer.
 
I think one big thing is missing here too.....manufacturers have to make products that sell to the masses. The fact is most people don't have space outside of a stand for a skimmer. This being the case there is a bigger market for a short skimmer than a tall one regardless of the efficiency. Another thing to keep in mind is that the tube skimmer had gone pretty stagnant and people were modding them left and right and posting how to's. This takes away from new business for the manufacturers. Introducing something that looks different and may or may not be more efficient means new sales for the manufacturers. Compare this to cars....we see refreshed cars every couple of years to get people to buy new. I am not saying the cone is good, bad or otherwise....just saying there are more reasons to introduce something new than just a better design.

Now, I will say that the focus on energy consumption has pushed new designs that appear to be more efficient. I am not sure there is enough use yet to draw any firm conclusions. The cone looks cool and there are some design aspects that seem to indicate an improved efficiency for the pump at the least and potentially the skimmer as a whole.

My final thought is that we should focus this thread on how the Cone skimmer works/doesn't work, where it is a design improvement or decrement, where the Cone skimmer gets the nod for technology improvement or incorporation of some design that we hadn't seen before and how that works. I think the cone shape of the body is an improvement for transitions sake. Does it make a night and day difference....don't know.
 
Wow I see we got a few posts yesterday:D

Ok thier are to many posts to go through and answer point to point, so allow me to just give an overall. At no time have I endorsed a skimmer type or design, neither one I came up with or one I have seen.
JCTewks and Luke I think you are misunderstanding me. Protien skimming has been studied to death (1000's of studies) from aquaculture to protien recovery to food making all studing the things we are talking about. For the sake of our talk it boils down to two things
1. We are trying to remove protiens and other foriegn material from our reef tanks. In doing this their is a process, the process is to break organic molecules from water gobblets and then reattach them to clean air bubbles and then have them removed from the system.
2. designing a unit and accomplishes the above.

Number one is carved in stone, it is fact. It is governed by laws/principles. The L/P that govern this are dwell time, bombardment rate and purity coefficient. Thier is none more important then the other, this is where all the studies are done, the numbers I through out thier are the results. Take them or leave them.
Number 2 is a whole other animal, this is where opinion and all the other BS tends to come into play.
All I have said is that in any skimmer design one should apply number 1 to it above all else. In our hobby folks are coming up with all sorts of designs, they all seem to be directed towards the making of bubbles (ie: I make mine with air stone yours is made with a venturi pump) its not all about that, that is just a very small part of the process.

on some other comments.
Luke, I agree, single pass skimmers are better, recirc tends to destabalize the bubbles and allows protiens back in. The 85/15 ratio is solid, I just dont think you understood me, dont look at the whole skimmer, just look at the portion below the skimmer where the bubbles are still mixing in the water, thats where the ration applies, the foam column is a whole different thing. On the clear skimmate, if you look I qualified that remark with another post. Most protiens are clear, but they are bound to others and other materials that have color. The point was that with skimmer that have way to much flow, allot of good things are frieght trained out of the system. I have seen this on alot of becketts, in regards to this cone skimmer I dont see it in the video linked. The tall skimmer vs short and so on, I didnt know that was an arguement?? to be honest it is easier to get the principles in a short fat skimmer. In my case, because I have a large ammount of water volume I needed a large mixing chamber, so the only tube I could find made me go a little taller (believe me, having a 18 inch round cup of skimmate over my head never really appelled to me.

JCTewks
Thier have been alot of studies that prove what is being removed, you can also see it yourself with the use of a microscope, to make it simple just say what doesnt is bad. Their is one thing that keeps coming up over and over again and you put it in your last post. It doesnt matter if a skimmer is short or tall, fat or skinny. Those things are just design concepts usually made for a particular market, as in you could have the best skimmer in the world, but if its to big, or to expencive or looks like crap it wont sell so manufactures work on things they think will capture the most market..period.
I'm just curious if the same results can be attained using Mike's math vs. Luke and I's "brute force" type skimmer.
Brilliant!!!!!!!!! although its not my math. The priciples/laws apply to every skimmer. The principles/laws can be achieved by any type of design, you can get it with needle wheel, mesh whell, venturi, air stone,short and fat, tall and skinny, square, cone triangle and so on and so on. Its seems thats where we all seem to let the wheels come off and get into one vs one, It is NOT NOT NOT that, their are many ways to achieve the goal, lets just not loose sight or change the goal to suit the design. Lets make the design accomplish the goal.

Ok more coffie now

Mike
 
Opps forgot the studies.

Laws of Foam Formation and Foam Fractionation. II. The Influence of Different Association Conditions on Surfactants, Glycerides, Sugar, and Salts on the Foam Fractionation of Albumin
Author: Syed Iftikhar Ahmad ab

Modeling Surfactant Removal in Foam Fractionation: I
Shulin Chen, Michael B. Timmons, James J. Bisogni Jr, Danel J. Aneshansley. -- Theoretical Development. Aquacultural Engineering,

Bubble size distribution in a bubble column applied to aquacultural systems
Chen, S., Timmons, M. B., Bisogni, J. J. & Aneshansley, D. J. . Aquacultural Engineering.

The effects of column height and diameter on the effectiveness of a continuous bubble fractionation system. Kown, B. T. Water Research

Venturi design parameters for air injection into a foam fractionation system. Lawson, T. B. PhD dissertation, The University of Maryland, College Park, MD, USA

Proteins at fluid interfaces : Adsorption layers and thin liquid films
Yampolskaya G, Platikanov D.
Department of Colloid Chemistry, Moscow State University, 117234 Moscow, Russia

Feasibility of using foam fractionation for the removal of dissolved and suspended solids from fish culture water.
Weeks, N. C., Timmons, M. B. & Chen, S. Aquacultural Engineering, Vol. 11, No. 4, pp. 251-265, 1992

Zeta potential measurement for air bubbles in protein solutions.
Phianmongkhol A, Varley J.
Department of Food Science and Technology, The University of Reading, Whiteknights, PO Box 226, Reading RG6 6AP, UK.

Shear and dilatational relaxation mechanisms of globular and flexible proteins at the hexadecane/water interface.
Freer EM, Yim KS, Fuller GG, Radke CJ.
Chemical Engineering Department, University of California, Berkeley, California 94720-1462, USA.

Interfacial rheological properties of adsorbed protein layers and surfactants: a review.Bos MA, van Vliet T.
Wageningen Centre for Food Sciences, Netherlands. [email protected]

Dynamics of protein and mixed protein/surfactant adsorption layers at the water/fluid interface.
Miller R, Fainerman VB, Makievski AV, Krägel J, Grigoriev DO, Kazakov VN, Sinyachenko OV.
MPI für Kolloid- und Grenzflächenforschung, Golm, Germany. miller@mpikg_golm.mpg.de

The role of interactions in defining the structure of mixed protein-surfactant interfaces.Mackie A, Wilde P.
Institute of Food Research, Norwich Research Park, Norwich, NR4 7UA, UK. [email protected]

Effect of bubble size on foam fractionation of ovalbumin.
Du L, Prokop A, Tanner RD.
Chemical Engineering Department, Vanderbilt University, Nashville, TN 37235, USA.

Modeling a protein foam fractionation process.
Du L, Loha V, Tanner RD.
Chemical Engineering Department, Vanderbilt University, Nashville, TN 37235, USA.

Measurement of bubble size distribution in protein foam fractionation column using capillary probe with photoelectric sensors.
Du L, Ding Y, Prokop A, Tanner RD.
Chemical Engineering Department, Vanderbilt University, Nashville, TN 37235, USA.

Foam fractionation of globular proteins.
Brown L, Narsimhan G, Wankat PC.
Department of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907.

Foam fractionation of proteins and enzymes. II. Performance and modelling.
Uraizee, F | Narsimhan, G
Enzyme and Microbial Technology [ENZYME MICROB. TECHNOL.]. Vol. 12, no. 4, pp. 315-316. 1990.

Surfactant Recovery from Water Using Foam Fractionation
Authors: Nopparat Tharapiwattananon a; John F. Scamehorn b; Somchai Osuwan a; Jeffrey H. Harwell b; Kenneth J. Haller a

Foam fractionation of proteins and enzymes. I, Applications
Auteur(s) / Author(s)
FAROOQ URAIZEE (1) ; GANESAN NARSIMHAN ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Purdue univ. , dep. agricultural eng., West lafayette IN 47907, ETATS-UNIS

Development of a multistaged foam fractionation column
R. C. Darton, , S. Supino and K. J. Sweeting
Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK

Tell me if you need more ;)

Mike
 
Okay, I understand that there is LOTS of science and research around foam fractitioning for industrial use...Oil refineries and wastewater treatment facilities are 2 of the big ones. But, in those industries it is clearly understood "what" they are wanting to accomplish/remove in fractitioning. In the Aquarium industry, it is not so black and white. Like I stated before, no one really knows "what" we are removing by skimming (exactly), nor how to test for those "what's". So, can we accurately use research done in the oil industry to make an assumption in the aquarium industry?

There are also other factors at play:
Inside of the skimmer body, redox levels decrease in long dwell time skimmers, allowing the chemical reactions to take place easier...now is this redox lowering a result of skimming, or a byproduct of skimming?
Is the DOC removal that occurs in the reaction chamber of the skimmer different from the DOC removal that happens in a large stacked foam head? If so, why? My thought is that both are needed and valuable. Here's my thought process (going along with what Mike has posted)...The hydrophobic substance are going to attach in the reaction chamber, where the bombardment rate is lower, then when the bubbles with the hydrophob's reach the foam head, the hydrophyllic substances can attach to the air/hydrophob's. In the stacked foam head, water is still passing and reacting with the air bubbles, just the water has longer contact time in the foam head as it uses gravity to fight the rising action of the air and drains from the foam head.
 
WOW, just saw your list Mike...impressive :D

Are any of those studies done specifically in the marine aquarium industry?

And what you were saying about not seeing the stacked foam head in the cone by watching the video...well, video definitely does not do these justice.
 
JCT with the links I put down a sampling of the differing studies. As in some on the breakdown of the organics, some of the rebinding, some on overall and then a bunch done for the aquaculture industry. Look at the aquaculture industry as the same as aquariums just on a massive scale. So to answer your question yes, now if your saying your only looking for one done on an 55 gallon aquarium with 5 fish 7 corals and is placed in New Jersey..well cant help you their.

And what you were saying about not seeing the stacked foam head in the cone by watching the video...well, video definitely does not do these justice.
Not sure what you are talking about here. Whats a stacked foam head. In looking at the video it definaltely looks like it produces enough foam, I dont see any issue with that. I dont know what the dwell time or bombardment rate is as I dont know the capacity of the unit. For all we know it could be dead on, but we seem to drift away from that and get into ____ is better then your ___.
In the Aquarium industry, it is not so black and white. Like I stated before, no one really knows "what" we are removing by skimming (exactly), nor how to test for those "what's". So, can we accurately use research done in the oil industry to make an assumption in the aquarium industry?
Yep it is, we know pretty much most of what is in the tank and what we are taking out, we also know how to measure it and so on. Your not going to find any real quality studies in the hobby because their no money their. In the aquaculture industry theirs billions, so their is where you look.
Inside of the skimmer body, redox levels decrease in long dwell time skimmers, allowing the chemical reactions to take place easier...now is this redox lowering a result of skimming, or a byproduct of skimming?
Both, but man theirs a whole other animal..
Inside of the skimmer body, redox levels decrease in long dwell time skimmers, allowing the chemical reactions to take place easier...now is this redox lowering a result of skimming, or a byproduct of skimming?
Is the DOC removal that occurs in the reaction chamber of the skimmer different from the DOC removal that happens in a large stacked foam head? If so, why? My thought is that both are needed and valuable. Here's my thought process (going along with what Mike has posted)...The hydrophobic substance are going to attach in the reaction chamber, where the bombardment rate is lower, then when the bubbles with the hydrophob's reach the foam head, the hydrophyllic substances can attach to the air/hydrophob's. In the stacked foam head, water is still passing and reacting with the air bubbles, just the water has longer contact time in the foam head as it uses gravity to fight the rising action of the air and drains from the foam head.
Good post! Their really isnt a lot of bombardment going on in the foam column, at that point the bubbles are pretty stacked/uniform and all moving slowly up. I am sure their is still binding going on, but at the same time thier is alot of disolving going on to, so its best just to write it off once it gets their. And that applies to any type of skimmer. The bombardment happens where clean air bubbles beat up on raw water molecules, this happens in the reaction chamber.


Mike
 
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