New Skimmer – Price is no Object!

[pjf]

Here is a proposed cheap standard home test to be done by all interested aquarists:

(1) Place an organic marker into aquarium at a standard concentration (X teaspoons for every 20 gallons).
(2) Run skimmer for a day or two. The skimmer will draw down the organic marker to a lower concentration and then face diminishing returns.
(3) Test organic marker concentration with a color card, UV fluorometer or infrared colorimeter.
(4) Post in Reef Central what the lowest concentration of that organic marker your skimmer was able to obtain.

The organic marker should be similar to "Olestra," so it will not be consumed by bacteria. Remember the artificial fat that was placed in Pringles so you will not be able to digest it and develop heart disease? It did cause "anal leakage" but that could be good for fish having problems with constipation.

[8BALL_99]

But that wont work....Way to many variables. You dont know how much organics are already in the water colum.. This will effect the amount of X the skimmer skims.. Not to metion you have water temp room temp salinity current ph, No3, Po3 ect ect levels. Not to mention how well a skimmer pulls out said marker is not a real world test....At best this gives you a general idea of how well a skimmer skims.. But we already have that so whats the point

Also just thought of this to.. Most everyone agrees that skimmer performance is changed depending on the amount of Co2 in the room.. So this would have to be monitored also...

[pjf]

Yes it will work and here is why:

(1) Skimmers filter based on the solubility of the organic compound. The less soluble the compound, the lower the skimmer can bring down its concentration. It doesn't matter if there are other organics in the water column. If the organic marker has solubility, S, then all organics with solubility, s < S will also be skimmed to a greater extent and all organics with solubility t > S will be skimmed to a lesser extent.

(2) The test will work when comparing two skimmers under the same conditions. These "binary" test results can be posted to allow ranking.

(3) If enough people perform the test and post results, there will be an averaging effect. Interferences with the test will be noted and the test will evolve. For example, if 8 out of 10 aquarists posted results claiming that CC skimmers did better than downdraft skimmers, we can conclude that the average CC skimmer is better than the average downdraft skimmer. Using detailed test reports, downdraft enthusiasts can "tune" their skimmers to do better in future testing.

This testing doesn't have to be controlled and perfect straight out of the box. We can start with the Salifert Organics test kit to compare the Remora against the Bubble King. The important thing is that we focus on the water quality, not the collection cup.

[Fiziksgeek]

Does the presents of other organic, (and/or inorganic I suppose) compounds affect the ability of the skimmer to skim?? Another way of asking the same question is: If there are more or less "other" unknown things in the water, would the skimmer still skim the target organic marker with the same effectiveness?

Originally posted by pjf

(1) Skimmers filter based on the solubility of the organic compound. The less soluble the compound, the lower the skimmer can bring down its concentration. It doesn't matter if there are other organics in the water column. If the organic marker has solubility, S, then all organics with solubility, s < S will also be skimmed to a greater extent and all organics with solubility t > S will be skimmed to a lesser extent.

[pjf]

Originally posted by Fiziksgeek
Does the presents of other organic, (and/or inorganic I suppose) compounds affect the ability of the skimmer to skim?? Another way of asking the same question is: If there are more or less "other" unknown things in the water, would the skimmer still skim the target organic marker with the same effectiveness?

Yes, the skimmer is affected by all of these variables. Over the course of a week or two (before your next water change), the concentration of the organic marker will be reduced to a point where the skimmer cannot appreciably skim it any more. This "point of diminishing returns" for your skimmer will be measured.

If you have a high turbulence, low dwell skimmer, it will skim less consistently than a low turbulence, high dwell skimmer.

[Napervegas]

What specific yellowing organic are you testing for. If you are going to use a marker in solution you must make sure the marker will not react and from new compounds in the tank which may or may not show up in the collection cup. If you want to send me a sample of your yellow water I will be happy to run it thru a gc-mass spectrometer and give you the results. Unless you know what you are looking for things like s

[pjf]

Thanks! I'd appreciate it if you can PM your address to me.

The yellowing compounds are called Gelbstoff. Currently, a carbon filter removes them. I believe that the Salifert Organics kit tests for phenols which make up part of Gelbstoff. I understand that phenols can be too soluble for skimmers to remove.

I am trying to find a slightly less soluble dissolved organic compound (DOC) that a reasonably good skimmer can remove. A test for this DOC can then be used to indicate the performance of a skimmer.

If you can find a common class of marine DOCs that is moderately removable by a skimmer and whose concentration (ppm) can be easily measured, I'd be very grateful. A "nice-to-have" would be a DOC that is not easily consumed by bacteria but I'll settle for what I can get now.

[Fiziksgeek]

So, if a skimmer's performance is affected by "other" things in the water, can you still draw reasonable conclusions from your proposed experiment? You might be able to claim the law of averages, but I am not so sure. To have reasonable results, I believe you would need similar water. The other variables in the experiment, (new skimmer, 3 years old, cleaned last week, never cleaned, water feed rate, etc, etc, etc.) would add a significant amount of noise to the results. But, if you had a large enough sample size, it would be simple to determine if the results are statistically significant or not. If i had to guess, I would guess not.

This would bring us back to Bean's proposed set up which would include dividing up water from a single system and testing multiple skimmers with it. This would ensure fair and even testing of the skimmers. In fact, I would suggest testing a minimum of 3 of each model, so that the results could be averaged. Even without this, its easy to see how quickly this would get out of hand when you start naming brands of skimmer, and why no one or no company would undertake such a task.

Maybe I am just being overly pessimistic about the ability of the average person to carry out experiments that would contribute to knowledge bank that I would trust...who knows....

Originally posted by pjf
Yes, the skimmer is affected by all of these variables. Over the course of a week or two (before your next water change), the concentration of the organic marker will be reduced to a point where the skimmer cannot appreciably skim it any more. This "point of diminishing returns" for your skimmer will be measured.

If you have a high turbulence, low dwell skimmer, it will skim less consistently than a low turbulence, high dwell skimmer.

[BeanAnimal]

Originally posted by pjf
A Remora in a cesspool will beat a Bubble King in the Waikiki Aquarium. It will fill its collection cup more quickly with nastier stuff. By testing the water columns with the cheap Salifert Organics kit, we can see that the Bubble King is doing a better job of maintaining water purity than the Remora.

With all due respect, that is not a meaningful comparison or example. Your talking about the need for science and then you propose an example like that?

This concept is not hard to understand. The key is to keep skimming after the easy-to-reach proteins are gone. If my 3-sentence explanation above is too much for you, here is an article comparing a downdraft skimmer to a counter-current skimmer by Richard Harker: http://www.tsunamiaquatic.com/page/page/1790661.htm.

I find your remarks more than a little condescending. Posts like that are a waste of everyone's time and certainly not called for. My remarks have been polite and on topic.

[BeanAnimal]

Originally posted by pjf
Yes it will work and here is why:

(1) Skimmers filter based on the solubility of the organic compound. The less soluble the compound, the lower the skimmer can bring down its concentration. It doesn't matter if there are other organics in the water column. If the organic marker has solubility, S, then all organics with solubility, s < S will also be skimmed to a greater extent and all organics with solubility t > S will be skimmed to a lesser extent.

But who is to say that your compound matches the solubility of the organics in a reef tank. What proportions? So when the skimmer is using bubbles to take out YOUR marker, it is not working on other proteins that the marker does not simulate.

In other words it is not any better of an indication than your Wakiki VS cess pool example. I understand what you are trying to propose, but the devil is in the details.

All you are going to show is which skimmer does a better job at removing YOUR marker, not real world protein concentrations of real world reef tanks.

So, this test is exactly counter your main point of this thread. I.E. We are using a meaningless test to rate skimmer performance.

(2) The test will work when comparing two skimmers under the same conditions. These "binary" test results can be posted to allow ranking.

As mentioned above, the test only show how well the skimmer works with your "marker". We could use food coloring, pudding, or any other "compound" and rank the the skimmers. The order may change. Unless your "marker" exactly mimics the proteins in the reef it is useless. Because every tank is different (back to your wakiki vs cess pool example) the results are fairly meaningless.


There are no easy answers. A simple test does not exist. That is why we use the volume, color and stink of the skimmate as an indicator of how well we are skimming. Add the apparent health of the the livestock and other indicators such as the interval between water changes before an observable deterioration in tank conditions is present. Most of us can tell if our skimmers are doing a decent job or not.

[8BALL_99]

I agree,,,,, exactly what I said.. Your marker is not a real world test. On top of that if the sample water isn't Exactly the same it will effect the results...At best this test you talk of would just give you a rough idea..

How did looking for a Replacement skimmer for a Tunze go into this anyway lol? I still say all this is pointless cause your not going to find a solution that takes up less space in your sump then you already have.. A really good skimmer will be larger then your Tunze and your Carbon reactor put together. Heck a skimmer that takes out 100% of every organic compound in the water would be Massive..If there was such a thing that is

[pjf]

Originally posted by BeanAnimal
[B]But who is to say that your compound matches the solubility of the organics in a reef tank. What proportions? So when the skimmer is using bubbles to take out YOUR marker, it is not working on other proteins that the marker does not simulate.

In other words it is not any better of an indication than your Wakiki VS cess pool example. I understand what you are trying to propose, but the devil is in the details.

All you are going to show is which skimmer does a better job at removing YOUR marker, not real world protein concentrations of real world reef tanks.

So, this test is exactly counter your main point of this thread. I.E. We are using a meaningless test to rate skimmer performance.

As mentioned above, the test only show how well the skimmer works with your "marker". We could use food coloring, pudding, or any other "compound" and rank the the skimmers. The order may change. Unless your "marker" exactly mimics the proteins in the reef it is useless. Because every tank is different (back to your wakiki vs cess pool example) the results are fairly meaningless.


There are no easy answers. A simple test does not exist. That is why we use the volume, color and stink of the skimmate as an indicator of how well we are skimming. Add the apparent health of the the livestock and other indicators such as the interval between water changes before an observable deterioration in tank conditions is present. Most of us can tell if our skimmers are doing a decent job or not.

Doesn't matter....

The test tank has water from a water change. There is no more nutrient import into the tank. After a few days, the skimmer will skim almost all that it can from the tank and reach a point of diminishing returns. That final test of DOC concentration will be indicative of that skimmer.

[BeanAnimal]

Nobody said testing could not evolve!

That does not mean that it is simple (as you keep insisting). It also does not mean that it is cheap nor does not mean that your methodology is correct.

The point is that at this time, there are no such tests. The general consensus leans towards the fact that there is not enough demand to make it worth developing the tests.

You have spent a lot of time pointing out that the "tests" we have now are not relevant, but the tests you propose are no more relevant once you look at the details.

[BeanAnimal]

Doesn't matter....

The test tank has water from a water change. There is no more nutrient import into the tank. After a few days, the skimmer will skim almost all that it can from the tank and reach a point of diminishing returns. That final test of DOC concentration will be indicative of that skimmer.

It most certainly does matter. Your marker is being skimmed out, taking the place of real protiens. It is NOT the same as the real protiens and therefore does not indicate anything other than which skimmer removes IT [the marker] faster.

How can you show that the marker is relevant to the actual protiens being skimmed in a given system? You can't.

It [your proposed test] is as non scientific and skewed as using the color or smell of the skimmate as an indicator.

[pjf]

I’ve proposed different tests in this thread. Let’s not get them mixed up. Let me repeat them and you can choose which you like or propose your own:

Originally posted by pjf
Here are a few simple tests, each of which can determine a skimmer’s ability to reduce DOC concentration:

• Colorimeter Test – take a sample of aquarium water and determine how much light is absorbed by Gelfstoff or other DOC’s (http://www.springerlink.com/content/7102263388112811/).

• Sump Test:

1. In your system, measure the level of a specific DOC type with the Salifert Organics test (or other test).
2. Stop your return pump but keep your skimmer running in your sump.
3. Test your sump with the Salifert Organics test (or test of your choice) every hour.
4. When the DOC concentration levels off, restart your return pump.
5. Your last measurement is the lowest concentration of that DOC that your skimmer can skim to.

• Comparative Test:

1. Take a large sample of nutrient-laden water from a large aquarium. This may be water from a water change that is normally discarded. Measure its alkenol concentration with the Salifert Organics test or other test. Optionally, you may dilute it with RO/DI water to a standard concentration.
2. Divide the water into two separate tanks of equal volume, each with a small circulation pump.
3. Place the two skimmers that you want to compare into the two separate tanks.
4. Periodically measure the alkenol concentration in the two tanks with the Salifert Organics test kit or other test.
5. The superior skimmer is the one that can produce the lower concentration of alkenols.

Originally posted by pjf
Here is a proposed cheap standard home test to be done by all interested aquarists:

(1) Place an organic marker into aquarium at a standard concentration (X teaspoons for every 20 gallons).
(2) Run skimmer for a day or two. The skimmer will draw down the organic marker to a lower concentration and then face diminishing returns.
(3) Test organic marker concentration with a color card, UV fluorometer or infrared colorimeter.
(4) Post in Reef Central what the lowest concentration of that organic marker your skimmer was able to obtain.

The organic marker should be similar to "Olestra," so it will not be consumed by bacteria. Remember the artificial fat that was placed in Pringles so you will not be able to digest it and develop heart disease? It did cause "anal leakage" but that could be good for fish having problems with constipation.

Originally posted by BeanAnimal
I would stick with the best skimmer you can afford. I would base my choice on observation and anecdote.

[BeanAnimal]

I am not confusing anything. I am basing my comments on what you have proposed and what you have used as the basis for this thread itself.

Your first set of tests is no different than myself or others has proposed, and is no different than observing which skimmer has nastier skimmate. What exactly is the salifert test indicating and how relevant is it to your beginning premise in this thread.

You second set of tests (the "marker" tests) is severally flawed (as mentioned above).

My point of view is that what you are proposing is a lot of trouble to glean very little information. To get a "lot" of information, the tests would have to be rather intricate. That means time and expense. So we are stuck with basics. That is exactly what we are doing and exactly what you have taken isssue with in this thread.

You just quoted my proposal. I will repeat here for clarity.
Observation of

The collection cup
The over health of the tank
The timespan between water changes needed to keep the tank healthy.
The overall color of the water and the amount of carbon needed to keep it as clear as desired.

Combine this with anecdotal evidence from people with similar and dissimilar skimmers and setups.

You can come up with a fairly good indication of how well your skimmer operates.

Would a simple and precise titration or similar test be nice? Of course it would. On the other hand, I am just fine without one.

[pjf]

Originally posted by BeanAnimal
You just quoted my proposal. I will repeat here for clarity.
Observation of

The collection cup
The over health of the tank
The timespan between water changes needed to keep the tank healthy.
The overall color of the water and the amount of carbon needed to keep it as clear as desired.

Combine this with anecdotal evidence from people with similar and dissimilar skimmers and setups.

You can come up with a fairly good indication of how well your skimmer operates.

Would a simple and precise titration or similar test be nice? Of course it would. On the other hand, I am just fine without one.

So you can compare wet skimmate with dry skimmate, add carbon, and tell which skimmer is working better?

Originally posted by BeanAnimal
I am not confusing anything. I am basing my comments on what you have proposed and what you have used as the basis for this thread itself.

No comment.

[BeanAnimal]

Why be so blatantly obtuse? The point is that the tests you propose are no more informative than casual observation. Your one line summation of my comments is conveniently simple with no context and it ignores just about everything that has been said. Furthermore, there are no simple tests available that will return the information YOU are looking for.

Regarding the carbon:
The carbon would be used IF and WHEN you determine that the skimmer is not removing enough yellowing compounds. How do you determine that? With your eyes. Try a different skimmer and try it without the carbon. Nothing profound about the methodology.

Again, nobody is saying that tests could not be developed. I (we?) are saying that the cost of doing so does not make sense for many reasons. The complexity of the tests, testing routine, etc just does not make sense when each and every tank is different.

This entire thread has nothing to do with you "looking for a new skimmer". It is about your ideas for improving skimming through testing and an attempt to present those ideas in an intellectual, if not condescending manner. There is nothing wrong with standing on a soapbox and kindly promoting your ideas. However, I think some of your ideas are borderline contradictory to your base premises put forth elsewhere in the thread.

Put another way, the conversation is fine, but as I have stated; I feel that you are looking for something that is simply not there and not even remotely economically feasible.

Your "No comment" remark certainly WAS a comment. Why quote me and then say that, other than to promote what I said as ignorantly wrong? Yet more condescension PJF. Can you not communicate without taking swipes at people? Your input would be so much more palatable and interesting without the one liners and obtuse comments.

[pjf]

So what skimmers are the best at removing yellowing compounds without carbon and ozone? Thanks!

[JCTewks]

I really don't think that Protein skimming is effective at removeing yellowing compounds...but my best guess at what would come slose to doing it would be a very tall counter current skimmer...either airstone driven like jnarowe's or a tall recirc NW like Hahnmeister is making.

IMO all of the new NW skimmers just aren't tall enough to be efeective at removing compounds that are extremely dissolvable, and the tall beckets and venturi skimmers move too much water through them to remove the said compounds.

But, pjf, you are looking to get a skimmer that will fit under your stand...so IMO there is really nothing out there that will fit under your stand and have a long enough dwell time to try and remove gelbstoff.

You would need to build a 6' x6" or 8"skimmer and put it next to your stand.

[hahnmeister]

I dont think skimming is so much about removing the yellowing compounds as preventing them. Sure, ozone can clear your water, but regular air... I think its more about removing organic matter before it goes through the nitrogen cycle. The conversion to nitrate by bacteria is what produces phosphates and the yellowing compound. So by removing the source, you are removing the potential. At that, almost any protein or nutrient that one of these bacteria can convert is capable of yellowing the water. So in the end, the idea of testing skimmers based on how tinted the water is is rather sound, as long as you take away the capability of live rock to digest from the equasion.

[pjf]

I think the current thinking is that for some proteins, 2 minutes of dwell time is necessary to bind with a bubble (http://www.hawkfish.org/snailman/skimmer101.htm). With a co-current skimmer perhaps height is necessary. On the other hand, a counter-current skimmer may be able to provide long dwell times with a shorter height.

I believe that there are many counter-current skimmers available but they are not marketed as such. Hahnmeister recommended a 22-inch skimmer, the Turboflotor 5000 Shorty (http://www.aqua-medic.com/turboflotor_5000_shorty.shtml) that promises long dwell times but the phrase, “counter-current,� is not in its description. Other “counter-current� skimmers include the relatively short recirculating skimmers.

There is a lot of anecdotal information about skimmers being able to remove Gelbstoff but I’ve yet to hear confirmation. Perhaps these skimmers used to be marketed but are no longer in the vogue.

[pjf]

Even if skimmers cannot remove Gelbstoff completely, an objective of improved skimmer performance should be the removal of more soluble proteins. Should the removal of the "source" of Gelbstoff be the objective, we still lose nothing by striving in this same direction.

You are correct that removing interferences, such as bacteria and live rock, is important. This is the reason why trying to analyze skimmate is like trying to analyze a "moving target." The bacteria in skimmate starts to degrade it as soon as it is collected. It is much easier to analyze the aquarium water column.

Here is a quote from Habib:

Originally posted by Habib
Generally speaking testing of skimmate is not a easy task and linking test results to skimmer efficiency can be very tricky.


Skimmate consists of a water phase and all sorts of particles. Many of the particles being organic and many of them living.

Skimmate's environment is totally different from the aquarium so it can boost the growth of certain bacteria and algae in the skimmate.

They will change the water chemistry rapidly, taking away chemicals, transforming them to something else and excreting chemicals in the skimmate water.

So its is a chaning environment and might not reflact the chemicals in the tank.


Probably the closest to measuring the skimamte might be by digesting the full sample chemically and have it measured for phosphorous, nitrogen and carbon.

Same would have to be done with a tank water sample.


Would it say something about skimmer efficiency? Not in all cases because what is the definition of skimmer efficiency?


Talking specifically to the organcs test, the color of the skimmate will highly confound the test. Besides what phase would be emasured? water only or also the surface of particles? If surface of particles as well then the skimmate would have to be mixed completely making a huge mess and samples would not be representative.

Even if there was no color to the skimmate and if it would be perfectly clear how would one know that the composition was not altered by the organisms living in the skimmate?


Skimmate is a complex thing to measure and has a rapidly changing chemistry, the redox value of skimmate changes rapidly as well.

(http://www.reefcentral.com/forums/sh...7#post10673417)

[GuySmilie]

This is becoming an interesting discussion.
Maybe a closer look at carbon's beneficial properties would lead to a more practical way to test efficiencies of a protein skimmer. Since Gelbstoff is the subject of concern, and carbon is the most popular medium to extract it from the water column, I snooped around a bit today and found this tidbit about 'iodine' and 'molasses number':

"Iodine is the most common standard adsorbate and is often used as a general measurement of carbon capacity. However, because of its small molecular size, Iodine more accurately defines the small pore or micropore volume of a carbon and thus reflects its ability to adsorb low molecular weight, small substances. Iodine number is defined as the milligrams of Iodine adsorbed by one gram of carbon, and it approximates the internal surface area (square meters per gram)."

"Molasses number is a measure of the degree of decolorization of a standard molasses solution. Because color pigments are large and cannot penetrate into small pores, the molasses number defines the large pore or macro pore volume of a carbon. It is used as a relative guideline for measuring the capacity of a carbon for larger adsorbate molecules."

Reference site

I don't know what 'molasses numbers' are all about, but instinct tells me that it's some sort of index used to scientifically define the clarity of molasses. Maybe that process can be utilized to measure seawater clarity as well, since the carbon folks tend to cite it often.

I know even less about chemistry, but according to this quote, maybe an iodine test can extrapolate data for measuring how well a skimmer removes low molecular weight matter.

Just food for thought....

[hahnmeister]

pjf, there are some 22" tall skimmers that I feel are 'enough' but dont get me wrong... I would rather just have 6' skimmers. The reality is that for many they just dont have the room under the stand. The turboflotors shorties are 24" tall, but the shorty2 model is 3', and the baby (my cousin uses one) is about 4'. The single and twin are 6' tall... and they are definately counter-current. The inlet is towards the top, and the water flow is downwards to the bottom... all the way coming into contact with a storm of bubbles coming up from the bottom.

But for all the reasons I see, and we have come up with, thats why I said that the only way to compare skimmers would be to set them up side by side on a very large system and see which one collects the most skimmate (condense the skimmate, and maybe even analyze it). One skimmer could collect just alot of one type of proteins though... enough to make it seem like a champ perhaps... but another may collect less overall, but a wider variety of DOC's (more air and shorter vs. taller and less air speculation). This is where skimmate analysis by the likes of Dr. Borneman comes into play.

http://forum.marinedepot.com/Topic52254-9-1.aspx