New Skimmer – Price is no Object!
- Thread starter pjf
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pjf
Premium Member
Countercurrent exchange means longer dwell time. You also get longer dwell time with tall skimmers. To reduce turbulence, you can lower the air intake, slow the countercurrent, or a number of other things.
Do you remember where you found information stating that "a tall countercurrent will produce the cleanest effluent?" Perhaps the source is a skimmer manufacturer that produces the countercurrent skimmers that I am looking for.
Thanks!
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hahnmeister
In Memoriam
Besides the extended dwell time, a countercurrent means that the water has to pass through the upward flow of bubbles for a great interface... rather than co-current like the ATI, where the water is most likely to travel with the same water from bottom to top. Other single pass skimmers, like ASMs, and RS series ER's, dont have much interface at all... the water can simply enter at the bottom of the skimmer and take the path of least resistance straight to the standpipe just below... with no real interface in the top of the skimmer at all. According to Holmes-Farley, some turbulence is a good idea... there is a point where things can be too calm in the skimmer (only the neck is the place where calmer is always better).
As far as who makes the claim of countercurrent being the best, I think Randy as well as Escobal are both on board with that. As far as taller being better, Escobal... but many others agree.
http://www.hawkfish.org/snailman/skimmer101.htm
According to Escobal, it takes upward of 2 minutes for some proteins to attach properly to a bubble after initial attraction.
As far as who makes the claim of countercurrent being the best, I think Randy as well as Escobal are both on board with that. As far as taller being better, Escobal... but many others agree.
http://www.hawkfish.org/snailman/skimmer101.htm
According to Escobal, it takes upward of 2 minutes for some proteins to attach properly to a bubble after initial attraction.
pjf
Premium Member
Back to Basics
Back to Basics
Hahnmeister,
Thanks for returning us to the fundamentals of skimming that seems to have been forgotten in the marketplace. A quote from the link you provided is key to lowering DOC levels: "It was estimated by Escobal that some proteins take upwards of 2 minutes contact time with air to attach properly."
I’m afraid that except for recirculating skimmers, countercurrent principles are not in the vogue. One problem is the lack of water column testing for skimmer performance. The Salifert Organics test may start to change that.
What skimmers in the marketplace today employ countercurrent flow, extended dwell times, small bubbles, and low reaction chamber turbulence with the objective of minimizing aquarium DOC concentration?
Skimmers over 26†tall will be a tight fit in my cabinet and a floor standing unit must meet wife approval but I'm very interested in what you have found.
Thanks!
FYI, I looked at the specifications for Schuran’s freshwater skimmers (http://www.schuran.com/freshwater/abschaeumer_e.html). As soon as I get a response from Schuran about neck dimensions, I’ll post the air flow to neck area ratio.
Back to Basics
Hahnmeister,
Thanks for returning us to the fundamentals of skimming that seems to have been forgotten in the marketplace. A quote from the link you provided is key to lowering DOC levels: "It was estimated by Escobal that some proteins take upwards of 2 minutes contact time with air to attach properly."
I’m afraid that except for recirculating skimmers, countercurrent principles are not in the vogue. One problem is the lack of water column testing for skimmer performance. The Salifert Organics test may start to change that.
What skimmers in the marketplace today employ countercurrent flow, extended dwell times, small bubbles, and low reaction chamber turbulence with the objective of minimizing aquarium DOC concentration?
Skimmers over 26†tall will be a tight fit in my cabinet and a floor standing unit must meet wife approval but I'm very interested in what you have found.
Thanks!
FYI, I looked at the specifications for Schuran’s freshwater skimmers (http://www.schuran.com/freshwater/abschaeumer_e.html). As soon as I get a response from Schuran about neck dimensions, I’ll post the air flow to neck area ratio.
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glassbox-design
New member
pjf, good thread...stirring the pot 
i just read a thread over in z-land and it made me think of an algae based reef i had set up.
it utilized an ETSS skimmer and as the algae became established, skimmate decreased and yellowing of the water increased. the only way i was able to remove the gelbstoff was with carbon....from what i understand ozone will also work, but i have never used it personally.
before the ETSS, i had a venturi and NW on the system...i dont believe they put a dent in the yellowing either.
i just read a thread over in z-land and it made me think of an algae based reef i had set up.
it utilized an ETSS skimmer and as the algae became established, skimmate decreased and yellowing of the water increased. the only way i was able to remove the gelbstoff was with carbon....from what i understand ozone will also work, but i have never used it personally.
before the ETSS, i had a venturi and NW on the system...i dont believe they put a dent in the yellowing either.
stony_corals
New member
That's a good link.... however, the information is a summary of Escobal and as such, it's pro-counter current. While contact time, etc are all good, if I go by Escobal and have 75gph flow through on my 100 gall tank, it may be efficient, but how effective is it? (I do believe that counter currents are really good, so don't slap me for saying that.) Effectiveness, meaning a function of how much of the system can I filter? I could put a beckett (downdraft) on the same system and still maintain very high water purity, may be higher than with the properly sized counter current.
manderx
New member
no. the real magic in countercurrent exchange is not about dwell time, but about maximizing the gradient (and therefore in theory total transfer) between the water/bubbles for as much of the dwell time as possible. i strongly suggest you read up on it. i would not consider any of the recirculating skimmers that i know of as countercurrent, even though they do feed input water near the top and exit the bottom, just too much mixing and turbulence within.
wiki came up first on google. if nothing else look at the pic.
http://en.wikipedia.org/wiki/Countercurrent_exchange
is there a new organics test from salifert? i got that one last year or so and it was absolutely worthless. the 'scale' was something like this:
"if it's clear you probably don't have an organics problem
if it's slightly yellow you might have an organics problem
if it's yellow you probably have an organics problem"
making any comparisons other than night&day would need a colorimeter of some sort. i dunno if you could use a hanna po4 meter for unscaled comparisons since it reads blue and this is yellow, but it might be worth a try.
Jim_S
Timo Boll
I think you guys are looking way too far into this.
There is no solid/empirical data that can effectively measure a skimmer's performance. Too many variables from tank to tank as well. Some skimmers are more effective than others due to design, air intake, etc., but too many variables to test this accurately. And even if there was a rock solid way, skimmer manufactures probably wouldn't even want to acknowlege it. Too much money at stake.
I would like a car that doubles as a boat. But even though they have been developing boats for centuries, and cars for a century, there still is no practical/popular way to do this. So the best option is to buy one of each, even though the boat will just sit during the winter months.
So what I am saying in this analogy, is that running different types of filtration is the best way keep your tanks water crystal clear for now. There is no super-special skimmer that will take care of all of your filtration needs. Sorry, it just doesn't exist. Not for $100, not for $5000.
I run a skimmer, a refugium and carbon. Keeps my water crystal clear.
Just my opinion on this matter.
Jim
There is no solid/empirical data that can effectively measure a skimmer's performance. Too many variables from tank to tank as well. Some skimmers are more effective than others due to design, air intake, etc., but too many variables to test this accurately. And even if there was a rock solid way, skimmer manufactures probably wouldn't even want to acknowlege it. Too much money at stake.
I would like a car that doubles as a boat. But even though they have been developing boats for centuries, and cars for a century, there still is no practical/popular way to do this. So the best option is to buy one of each, even though the boat will just sit during the winter months.
So what I am saying in this analogy, is that running different types of filtration is the best way keep your tanks water crystal clear for now. There is no super-special skimmer that will take care of all of your filtration needs. Sorry, it just doesn't exist. Not for $100, not for $5000.
I run a skimmer, a refugium and carbon. Keeps my water crystal clear.
Just my opinion on this matter.
Jim
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Pyrrhus
New member
Yeah, but now they have a ATV/Personal watercraft!
http://www.metacafe.com/watch/781170/jetski_or_atv/
BeanAnimal
Premium Member
I have thought long and hard about this. The only way that you could even get a start, would be to use ocean water directly (endless supply) and setup to feed several skimmers in question. You would need multiple skimmers of each type and their outputs would need to discharge so that they could not be mixed with the inputs. The test would be time based.
You could then argue about the volume of skimmate, the color, the dry weight, whatever. You still would not end up with a definitive answer as to which skimmer was better.
I suppose you could take a very large sample of yellowed ocean water and run a similar test. Divide the water into equal portions and skim it for a period of time. You could measure the transmission of light through the water to determine which skimmer did a better job with the yellowing compounds.
I am just not sure any of it would be worth the trouble and would leave a lot open to debate no matter how you ran the test and controlled the variables.
So... in a long winded way, I agree with jimdogg.
You could then argue about the volume of skimmate, the color, the dry weight, whatever. You still would not end up with a definitive answer as to which skimmer was better.
I suppose you could take a very large sample of yellowed ocean water and run a similar test. Divide the water into equal portions and skim it for a period of time. You could measure the transmission of light through the water to determine which skimmer did a better job with the yellowing compounds.
I am just not sure any of it would be worth the trouble and would leave a lot open to debate no matter how you ran the test and controlled the variables.
So... in a long winded way, I agree with jimdogg.
Fishbulb2
New member
What about using a fixed salinity and a known concentration of given organic compound. Then you could measure how much of that compound has been removed from a given volume, for a given amount of time. Of course this would be specific to only that chosen compound, but it would still probably be relevant to other compounds too. I think of it like how RO membranes report sodium rejection. They measure this under strict laboratory conditions and then it tends to hold true for many other ions as well. Anyways, this is how I would go about it as well.
Unfortunately I don't think using real ocean water would be a good idea. It is way to variable from day to day. I live on the beach here in SoCal and the amount of stuff you would skim out would change on a daily basis. We get tons of bacterial warnings and contamination warnings. Some days the water gets so bad that large balls of foam form on the water line and the next day it will fine again. I would just use fixed known artificial sea salt to make up the "industrial standard".
Unfortunately I don't think using real ocean water would be a good idea. It is way to variable from day to day. I live on the beach here in SoCal and the amount of stuff you would skim out would change on a daily basis. We get tons of bacterial warnings and contamination warnings. Some days the water gets so bad that large balls of foam form on the water line and the next day it will fine again. I would just use fixed known artificial sea salt to make up the "industrial standard".
pjf
Premium Member
Simple Skimmer Performance Tests
Simple Skimmer Performance Tests
Here are a few simple tests, each of which can determine a skimmer’s ability to reduce DOC concentration:
• Colorimeter Test â€"œ 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.
Simple Skimmer Performance Tests
Here are a few simple tests, each of which can determine a skimmer’s ability to reduce DOC concentration:
• Colorimeter Test â€"œ 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.
BeanAnimal
Premium Member
All of the skimmers would be sucking in the exact same mixture of water. That is the whole premise behind using the natural sea water
It takes one variable out of the problem.Similar threads
