Marine Depot Forums / TEAM Marine Depot / Corals and Coral Reefs - by Eric Borneman / Preliminary look at skimmate / Latest Posts

RE: Preliminary look at skimmate

Eric Borneman — Thu, 15 Oct 2009 06:16:51 GMT

Sadly, no. Although I can write back and see if anything else was done. I tried to keep communications with the collaborating parties open, but they just faded away - and one person to his credit did have an extended family issue to deal with. The other person turned out not to have the capacities needed to do the analyses needed and I have asked numerous people in chemistry labs who should be able to, but amazingly don't. So I looked up the possibilities of doing it myself, and it requires equipment we don't have, I don't have, and is very expensive.

But, I am not giving up and will probably try a workaround using a different protocol. It's not at the top of my list right now to do the work myself, but let me check in with the others first. Thanks for reminding me.

RE: Preliminary look at skimmate

sltloser — Wed, 14 Oct 2009 16:48:13 GMT

hey eric, i know you're a very busy person but was wondering if that pm you got ever helped? or if you've done anymore research on the topic?

RE: Preliminary look at skimmate

Eric Borneman — Sun, 01 Jun 2008 06:36:03 GMT

Thanks, Rob. I actually have a pm right now that might be of help in finishing this. ::crossing fingers:::

RE: Preliminary look at skimmate

Bob the (reef) Builder — Fri, 30 May 2008 11:18:27 GMT

Wow, fascinating thread, I hope that you get the chance to conclude the study at some point.

I think that it really could be a font of so many more questions that nobody really seems to have investigated or thought much about.

Thanks

Rob.

RE: Preliminary look at skimmate

Eric Borneman — Wed, 28 May 2008 07:00:57 GMT

HI Brady:

I have all the samples in the freezer, and one day will get around to getting a good analysis. To send them off costs too much and I need to make a friend who does this sort of work. I would also get fresh samples when that happens. I will update the thread when that happens.

RE: Preliminary look at skimmate

sltloser — Tue, 27 May 2008 20:53:56 GMT

so i just got done reading most of the 21 pages of the article haha....Great research to eric and everyone involved...Were you ever able to come up with a conclution?

-Brady

RE: Preliminary look at skimmate

Reefski — Fri, 08 Feb 2008 07:08:32 GMT

i too want to know.

theoretically skimmers take out DOC's, which would be kind of an end product of metabolism. however they also takes out many other things it seems.

there must be some kind of nutrient export, if not a skimmer what, Miracle mud, macroalgae? coral growth? so many choices of how to run a tank.

my tank has been skimmerless for a couple of years. corals are doing fine despite the presence of some unsightly cyano.

RE: Preliminary look at skimmate

Tim Parkinson — Fri, 08 Feb 2008 05:03:06 GMT

Hi Eric,

Did you form a conclusion? or have any more thoughts?

RE: Preliminary look at skimmate

JasonSquared — Wed, 26 Dec 2007 21:41:07 GMT

Is this thread dead?

RE: Preliminary look at skimmate

TosT — Tue, 21 Aug 2007 16:13:55 GMT

Great info Charles, and happy belated birthday BTW. So it seems like bacteria can move really quickly in the field of view. Flagella seem to be the equivalent of a high speed motor!

Absolutely, my modest microscope does have a 100X objective and I have used it a couple of times, but I try not to because I haven't bought the special paper to clean the immersion oil from the objective lense. But still, at 1000X they are really small, most of them are just dots moving around. The slightly larger ones, which are long (spirillum?), seem to move in a quick "s" fashion, which kinda sounds like nematodes but I really doubt they get that small. But yeah, I've been meaning to get safranin or something like that. What do you recommend?

Thanks for your input.

RE: Preliminary look at skimmate

Spracklcat — Tue, 21 Aug 2007 04:23:26 GMT

If you're looking for bacteria, you will have to use a higher magnification--typically a 100x objective and a 10x ocular =1000x Also, you will have an easier time seeing bacteria if you use a staining system.

As for what that ciliate is that you found, I don't know--I'd call it "zooplankton" But it's too big to be a bacterium.

RE: Preliminary look at skimmate

charlesr1958 — Tue, 21 Aug 2007 04:15:18 GMT

The more I hear of what is being found in skimmate, the less I would want to run a skimmer, just seems like an awfull lot of good food is being wasted. Not sure what dissolved organics or "by-products" are being removed that might justify a skimmer, but have a feeling that a good grade of carbon would take care of any "nastys" while leaving behind the "goodies".

Thanks to google, I was surprised to learn that some bacteria are fairly fast for their size and act more like a ciliate than what I had thought of as being bacteria.

" Some bacteria can move. A few can glide across a surface and some aquatic species can control their buoyancy, and thus their depth in the water, through internal gas vesicles (bubbles). Most bacteria however move by means of one or more flagella (singular flagellum). A bacteria that possesses one or more flagella is termed 'flagellated' and there are 3 main different styles of flagellation. If the bacterium has just one or two flagella placed at either one, or both ends of its cell (this applies to rod and spirochaetic bacteria) it is said to have Polar Flagellation. A bunch of flagella coming from one end of the cell is called Lophotrichous flagellation (tufted) and if it the flagella come out at random points around the cell it is called Peritrichous Flagellation. The flagella are not straight but are twisted in a sort of wave shape. The distance between each wave crest or trough is fixed for a species and is often important in identification. Bacteria move not by flexing their flagella the way a fish flexes its tail and fins, but by rotating them like a propeller. This can enable them to obtain speeds as high as 0.00017 kilometres per hour. This may not seem very fast, but to put it into perpsective remember that we are talking about very small organisms. Looked at another way, they are travelling at about 50-60 body lengths per second. This would be the equivalent of a 1.8 metre (6 feet) tall man running at 100 metres per second, 9 times faster than the world record. Cheetahs, are the fastest animals on land but even they only move at about 25 body lengths per second.

Type of Flagellation	Bacterial Species
Polar flagellation	Rhodospirillum centenum
Lophotrichous flagellation	Rhodospirillum photometricum
Peritrichous flagellation	Salmonella typhi "

RE: Preliminary look at skimmate

TosT — Mon, 20 Aug 2007 20:51:36 GMT

Sorry for the double post. The attachment didn't seem to work.

Skimmate:
http://i13.photobucket.com/albums/a295/TostCR/aquariummicrofauna019.jpg
Detritus:
http://i13.photobucket.com/albums/a295/TostCR/skimmatesw001.jpg
http://i13.photobucket.com/albums/a295/TostCR/skimmatesw004.jpg
http://i13.photobucket.com/albums/a295/TostCR/skimmatesw006.jpg
http://i13.photobucket.com/albums/a295/TostCR/aquariummicrofauna024.jpg
Ciliate visible in the very center:
http://i13.photobucket.com/albums/a295/TostCR/skimmatesw003.jpg

RE: Preliminary look at skimmate

TosT — Mon, 20 Aug 2007 20:38:29 GMT

Here are a couple of pics of my skimmate. Seems to be basically lot's of detritus: fragments of multicellular algae, unicellular algae, spicules, fragments of exoskeletons, etc. On the other hand, there is a considerable amount of ciliates swimming around in the skimmate. I've also observed lot's of other, much smaller, motile microorganisms which are barely visible at 400X that I'm guessing are bacteria. Does anybody know how quickly can bacteria move around?

RE: Preliminary look at skimmate

CTReefer — Thu, 16 Aug 2007 09:10:26 GMT

steenmillinder (8/16/2007)

hi.. i'm setting up a 720 liter tank with predators so heavy load... is it wise to skim such system, or can i just save the money and use it to buy a larger sulpher reactor?

Not sure what you mean by "Predators"? Is this a fish only tank set up? If so, you should start a new thread rather than append this question here.

If you mean a "Denitrator" unit, I would not recommend one. They are notorious for not working properly & can wipe out the inhabitants of your tank if Sulphur is released. Finally, you can certainly use a PS on your system.

Steve

RE: Preliminary look at skimmate

steenmillinder — Thu, 16 Aug 2007 07:53:13 GMT

hi.. i'm setting up a 720 liter tank with predators so heavy load... is it wise to skim such system, or can i just save the money and use it to buy a larger sulpher reactor?

RE: Preliminary look at skimmate

icy1155 — Wed, 15 Aug 2007 20:20:54 GMT

Any updates on this project?

RE: Preliminary look at skimmate

Labman — Fri, 29 Jun 2007 04:55:50 GMT

I am so hoping to get to Macna this year as I think this is going to be the place to get all this info and more.. plus of course share a few drinks with both old and new friends.

RE: Preliminary look at skimmate

Alentino — Fri, 29 Jun 2007 04:39:23 GMT

Hi,

Any updates on this? Thanks.

RE: Preliminary look at skimmate

murraycamp — Mon, 11 Jun 2007 09:22:19 GMT

Eric, I know you are slammed, but do you have any guesses as to when you will have a chance to complete the final analysis on this project? Thanks!

RE: Preliminary look at skimmate

Eric Borneman — Mon, 23 Apr 2007 18:46:27 GMT

I just got back in town, have two papers due by week's end for a proceedings, and a thesis to finish. As soon as that is done, I will have this work out first thing along with the salt study works and elegance coral work.

RE: Preliminary look at skimmate

TosT — Tue, 17 Apr 2007 16:53:28 GMT

Any updates on this? How's the article coming?

RE: Preliminary look at skimmate

Warlan — Mon, 26 Mar 2007 17:05:07 GMT

Yes, it is sad the way scientists are reduced to conducting research. The flatlining of funding the last few years is really hurting the bio-med field. It has other side effects where faking of data becomes more prelavent, poorly reviewed papers are let through, politics effects grant awarding, etc... Some reckon that the US research will be set back 10 years. Heh, there are so many things that bother me with the system I shouldn't get started. Let's get this thread back on track, sorry for taking it off track.

P.S. good luck with your Ph.D. thesis!

RE: Preliminary look at skimmate

Eric Borneman — Mon, 26 Mar 2007 10:39:52 GMT

Yes, I am caught up in it, but I relate to you, too.

I started in ecology and evolution - a very hypothesis based field. After the retirement of my advisor, I moved to cell and molecular biology, where reserach isnot driven like this as you describe. Now, most papers and research in these fields goes on the notion that "its either there or its not" but many papers have been written that this is a fault of current research in these fields, and that statistical analyses and hypothesis driven experiments should still be the basis. So, I relate to my chagrin as I am having to fulfill both these requirements right now, and vastly prefer the cell bio way. But, the test suggested in this thread much more fall in line with traditional hypothesis deriven research.

Reefksi - there are a lot of tanks we drew skimmate from. Its a long thread, but its all here.

RE: Preliminary look at skimmate

Warlan — Mon, 26 Mar 2007 09:00:18 GMT

Bah, you are too caught up in the scientific method. I have yet to see someone actually use the method to the T in the laboratory. Perhaps it's the medical world. We never seek out to disprove our opposite. Never. We seek to gather enough evidence that supports our hypothesis. Generally, if experiments suggest the hypothesis is wrong, the project is abandoned if the results are not interesting, or another approach is attempted to support the hypothesis. A grant application or publication never reads 'Well we proved that it wasn't X, Y, or Z so it must be A which supports our hypothesis.' No, the normal path would entail that it must be A because X, Y, and Z suggest that it must it so.

RE: Preliminary look at skimmate

Reefski — Mon, 26 Mar 2007 08:42:19 GMT

Eric--

can you tell us how big the tank is that you took you skimmate from?

how many grams of food a day do you feed that tank?

how much dry wt skimmate per day did you collect?

RE: Preliminary look at skimmate

Eric Borneman — Mon, 26 Mar 2007 06:42:26 GMT

Thanks, Ed.

Benj, I'll just let your comments stand (can't spend that much time on a post again and have to get to lab) but I would remind you that hypotheses are never proved correct. You disprove their opposite to what is a hopefully highly insignificant level. After I posted I realized I had a good anaolgy.

When you do a phosphate "test", you are taking a water sample and measuring the phosphate. You could then try to break down that phosphate into orthophosphates, metaphosphates, polyphosphates, etc. You could also try to determine if metal ions like Mg or Zn were bound, etc. But, doing that initial water test isn't an experiment. It's a reading, a measurement.

Now, if I took a whole bunch of readings and then analyzed them to find a mean phosphate level for a population of aquarists based on a random sampling, that's a statistical test.

If my hypothesis was "aquarists with tanks in cities with have higher phosphates than aquarists in rural areas" and proceed to test that, that is an experiment.

I have a bunch of samples, possibly random, and I might be able to say something statistically significant about those samples, but I still don't consider it an experiment. Not yet, anyway.

RE: Preliminary look at skimmate

Ed Ricketts — Sun, 25 Mar 2007 21:36:10 GMT

Eric,
Great work, and even though some have questions regarding whether or not "efficiency" is the question, I think it is quite eye-openning to think that the DIY ghetto skimmer I built back in the 90's, or the Mac-Daddy $500 monstrosity that you can get for "skimming" might NOT be necessary. Yes, it might. But you have asked the fundamental question, "Yes, it's gunky looking but what is IT exactly?"

That to me is a paradigm shift. I didn't even consider that it was good, I just wanted it out - out of the tank, out of the cup, (and my fiancee') out of the kitchen sink!

Appreciate Benj's thoughts. He does have a couple of valid points regarding whether or not this is "quasi-experimental" (was that it?) but it occurs to me that this is basic research, with some venture into applied science. But generally, not unlike being the first guy to walk 600 miles straight into the jungle, equipped only with a bird net, bug spray, formalin and a note book, just to see what's there. We'll get to all the interrelatedness of it later, but before we connect the dots, we need to know what the DOTS are.

By the way it does make perfect sense to me that the nitrates in the tank and the dry or wet skimmate measure pretty much the same. I expect the "nitrates" I'm skimming out are (presumably) un-measurable Nitrogen that is tied up in those amphipathic molecules that we presume are in the gunk. Still gets the nitrogen out of the tank, out of the hands of the bacteria that might utilize/breakdown/release nitrogen ultimately. It's nitrogen, but not in the form Dr. Salifert has us measuring it. Presumably,...

Lab time in your youth is precious, and applying yourself to better understand your surroundings is a noble endeavor. We benefit because you have chosen to type these observations for an audience of a few interested onlookers. Keep it up...

RE: Preliminary look at skimmate

Warlan — Sun, 25 Mar 2007 18:06:04 GMT

Well, not to waste your time anymore. I will leave this thread on a couple of notes.

1)Measuring an unknown quantity has an unspoken hypothesis. That would be: "what is in this stuff". Hypothesis are almost rarely proved correct unless they are so broad that it isn't even worth having. Hypothesis are very often adapted to the results, therefore you do not 'need' one. A starting hypothesis is merely a guide and could be as broad as: What do protein skimmers really remove from the water. I was giving an example because it honestly is not that important and will likely be wrong. I have a Masters in Molecular Genetics and my wife has a Ph.D. in Experimental Medicine, just to qualify my background.

2)Finding out what a skimmer removes, in my mind, has nothing to do with its efficiency. The efficiency of a skimmer is how well it removes what it is supposed to remove versus other skimmers. What you are doing will not in anyway shape or form determine efficiency (as your current experiments are setup) and as I define efficiency. Given that we already know protein skimmers remove things that are food sources for the very things we want to feed I don't think efficiency is of importance for what I want to know. I don't care if Deltec skims X component better than a ASM. As you have already begun to question, which is a hypothesis in itself and thus requires experiments to tease out (which you are doing), is what all does a protein skimmer take out. Is it only proteins, only single celled organisms, only certain types of proteins, etc. Some of that is already known, some of it you have found out, and some of it you will find out in the future.

3)Twice you said I was changing my hypothesis. Proteins are organics last I checked. If I am measuring proteins skimmed out, which are organics and proteins left in the tank, which are organics then I am measuring organics! However, if I find the proteins left in the tank are hydrophillic then I have answered my hypothesis. So I fail to see why you twice attempted to rebuff my hypothesis...

The hypothesis for the fish experiment would likely differ, and that is looking ahead. Something one must keep in mind.

4)In the end your hypothesis is: What are the different types of particles that can be removed from a skimmer (ranging from molecules to higher life forms). I suppose if you find it is removing a ton of stuff that would normally serve as a food source for your aquarium then you have your answer, at least in part.

In the end I understand what you really want to look at a bit better and it differs from what I was questioning. That said, I think your results will be fascinating and will make us really question the use of these energy hogging, source of food removing, noise making mechanical filters.

Hopefully, I can find some time to contribute with some experiments of my own.

Best of luck,

Benj

RE: Preliminary look at skimmate

Eric Borneman — Sat, 24 Mar 2007 07:42:15 GMT

1.
>You don't need a hypothesis to begin an experiment. Any unknown quantity can justify an experiment. But if you need one: Protein skimmers are unable to isolate hydrophillic (fully dissolved) proteins. Now someone gets to prove me wrong (including myself). <<

Well, yes, you kind of do have to have a hypothesis. Unknown quantities are just measurements. Your described efforts are definitely ones that would be a controlled experiment and require a hypothesis.

As to your hypothesis:
a. proteins are not all hydrophilic.
b. protein skimmers remove things other than proteins
c. the material you suggest adding will contain more than proteins.

side question I would ask - is the removal of proteins desirable? If you will note, many products are "amino acid" supplements. Why would one theoretically remove proteins and add amino acids right back again? Also, protein skimmers are generally believed to maintain high water quality. How? By removing proteins or by removing proteins and other things? What are those other things? Is it effective? These last more basic questions are what I am looking at. Sort of like crawling before walking.

2.
>>> Measuring phosphate and nitrate from various samples. Filtering skimmate through various pore sizes. Seems like experiments to me. Simple? Yes. Still an experiment.<<

quasi-experiment.

3.
>>Sorry, I understood you were doing a PhD.<<

a. I am. But this is not my thesis, not is it even funded work.

>>Filters for vacuum sources are quite common and would easily fit most skimmers. Guess they aren't that common in marine biology.<<

a. yes, filters for vacuum sources are common. HEPA filters for a given protein skimmer are not.
b. filters clog quickly, especially efficinent ones. This would then be another variable for the potential efficiency of the skimmer.

4.
>>>Hey, I never said it was beneficial! The idea is the removal of a particulate or ogranic material. Let me check...ah yea food falls into that category.<<

a. right. That's what I am doing.

5.
>>>No, this wouldn't require multiple skimmers. You are checking total ability of a skimmer to remove organics and particulate material. In a controller environment such as this you could introduce various matter like phytoplankton, cyclopeeze, etc...<<

a. First, this is not the hypothesis you proposed. You said hydrophilic proteins. Now we are talking about particulates and prior to this organics, phosphate, carbon, etc.
b. This experiment, as I mentioned, would logically be a measure of the ability of a skimmer to remove material added to a tank. It would only be valid for that skimmer, and you would need replicates and a control.

6.
>>>Yes, but I don't understand how you can determine what remains in a tank where you do not have records of precise input of food.<<

a. I have tank water samples and skimmate samples. There are the inputs and outputs over 12 hours. No water changes occurred.

>> Nevermind the route that the food is digested down the food chain. You are analyzing a sample for its composition, but that doesn't tell you what % of food input you put in is directly removed by a skimmer. <<

b. Because that is not the question I am asking. I am not interested at this time of what percentage of food added is removed by a given skimmer.

>>No? For example, do hydrophillic proteins have to be uptaken by bacteria/algae before they, in whole, are skimmed out? Without a controlled environment you wouldn't be able to answer that.<<

c. Exactly. A controlled experiment. With a hypothesis. As I said before. And these are not questions ready to be tested or answered yet. They are important questions, for sure. Understanding the nutrient dynamics of tanks is essential and also a very complicated and difficult thing to work out and test. One could spend years doing this. If anyone wants to or has the ability to start asking these questions and testing them, by all means get out of the armchair and start doing it. The faster data are gained, the sooner we have all the answers.

Again, as often happens, we see beyond and recognize that there are more questions to be answered. People may ave different questions they want answered. Eventually, baby step by baby step we start to put together a picture of what happens. My baby step here is looking at what skimmers remove and if there are variations, relationships, etc. with certain factors to the limited extent I can determine them at this time. If something stands out, that one factor may require a whole series of other experiments to tease out variables such as the one you mention above. The whole picture cannot be painted at once.

7.
>>Well, I would probably make the fish a third experiment. You ask a question then answer it yourself. I don't get it. In the end you want to see total dissolved organics vs skimmed organics. What algae and bacteria take up may or may not be relevant, especially if they are being skimmed out.<<

a. Again, your hypothesis was hydrophiolic proteins. Now it is dissolved organics.
b. What is the nature of this third experiment? What is the hypothesis?
c. "You ask a question then answer it yourself". Exactly. This is your question. Answer it yourself.

8.
>>>Did I ask you to test every skimmer?<<

a. No, but my point is that even with a proper experimental design, your ideas here would only be valid for that skimmer.

>> Am I asking for efficiency? I don't think so.<<

b. Yes, absolutely you are asking about the ability of a skimmer to remove (hydrophilic proteins, carbon, nitrogen, phosphate, particulates, food, dissolved organics). That is a measure of its efficiency.

>> Most analysis of skimmate to date has been very basic. For me, if a skimmer can only remove a certain type of organics I might decide it isn't worth using. As far as I can tell siphoning works a hell of a lot better than skimming.<<

c. You very well might be right. That's another test. But, without knowing what skimmers remove, it would be hard to say, wouldn't it? Hence why I am starting at square 1.

RE: Preliminary look at skimmate

spazz — Fri, 23 Mar 2007 23:31:26 GMT

As always this is a very interesting topic Eric. I will be looking forward to the final results, and your opinions as to what skimmers are doing to our tanks. weather it be good or bad the results will be informative and give people a better idea of what a skimmer removes. I just wish I would have know of this study sooner. I could have gotten you some samples from 2 privately owned large reef tanks with skimmers that compare in size the rk2 skimmers you got smaples from.

is there a release date set for this article?

keep on trucking Eric. ha ha ha ha ha

scott

RE: Preliminary look at skimmate

Warlan — Fri, 23 Mar 2007 08:52:55 GMT

Ahh good, didn't want to ruffle any feathers.

RE: Preliminary look at skimmate

Eric Borneman — Fri, 23 Mar 2007 08:42:45 GMT

I didn't take it as a critique at all. I will repsond in depth later - have work to do now. Thanks for the reply.

RE: Preliminary look at skimmate

Warlan — Fri, 23 Mar 2007 07:42:32 GMT

Several things:

1. You consider these experiments, and an experiment begins with a hypothesis. What is the hypothesis of your proposed experiments? I don't see that there is one.
>>>You don't need a hypothesis to begin an experiment. Any unknown quantity can justify an experiment. But if you need one: Protein skimmers are unable to isolate hydrophillic (fully dissolved) proteins. Now someone gets to prove me wrong (including myself).

2. What I am doing, at this point, are not experiments per se. They are analyses of samples. Now, I can do tests on them and do regressions and correlations with various factors. But, they aren't experiments.
>>> Measuring phosphate and nitrate from various samples. Filtering skimmate through various pore sizes. Seems like experiments to me. Simple? Yes. Still an experiment.

>>Experiment 1:

Make a tank with just saltwater freshly madeup. Add known weight of pellet food or flake food(something dry with no water).<<

All food has water in it, so it would need to be baked to dry off water. How do you know there aren't organics in the seawater mix? Let's assume there aren't.
>>>Yep, baking would be good. Organics in the seawater? Well you could probably get away with making a NaCl 'seawater' for the purposes of the hypothesis. Pretty cheap labgrade. But if you want to go with hobby grade you could test for proteins or CNP before food is adding. That would be your baseline.

>> Use powerhead for circulation, seal tank,<<

Why seal the tank - to prevent airborne dust and debris?

>>>Exactly.

>>add hepa filter on skimmer air intake.<<

A HEPA filter on the intake??? Wow. I don't have a HEPA filter for a skimmer
>>>Sorry, I understood you were doing a PhD. Filters for vacuum sources are quite common and would easily fit most skimmers. Guess they aren't that common in marine biology.

>> Skim until no visible food is in water, collect waste at multiple intervals and check dry weight.<<

Problem 1. Is removal of food a beneficial role of skimmers? I thought food was supposed to be eaten. Anyway, the idea here is removal of a particulate or organic material.
Problem 2. This requires multiple replicates and a control. The control would be just the plain seawater. Then, this means multiple skimmers of the same type, and I have already shown that two identical skimmers do not perform equally on the same or different tanks.
>>>Hey, I never said it was beneficial! The idea is the removal of a particulate or ogranic material. Let me check...ah yea food falls into that category.

>>>No, this wouldn't require multiple skimmers. You are checking total ability of a skimmer to remove organics and particulate material. In a controller environment such as this you could introduce various matter like phytoplankton, cyclopeeze, etc...

>.Then check CNP or protein concentration of tank water vs skimmate.<<

OK, this would show what is removed versus what remains. Of course, I'm already doing that with the various tanks.
>>>Yes, but I don't understand how you can determine what remains in a tank where you do not have records of precise input of food. Nevermind the route that the food is digested down the food chain. You are analyzing a sample for its composition, but that doesn't tell you what % of food input you put in is directly removed by a skimmer. No? For example, do hydrophillic proteins have to be uptaken by bacteria/algae before they, in whole, are skimmed out? Without a controlled environment you wouldn't be able to answer that.

>>Experiment 2:

Take tank water from a reef system (has bacteria and algae) add one mature fish. Run with skimmer for at least 1 week adding known quantities of food. Repeat above experiment (run skimmer until poop is gone).<<

This makes no sense. Why the fish? How do you measure remaining poop or other waste? How do you measure uptake by bacteria and algae? You would have to do counts and also all the issues as above.
>>>Well, I would probably make the fish a third experiment. You ask a question then answer it yourself. I don't get it. In the end you want to see total dissolved organics vs skimmed organics. What algae and bacteria take up may or may not be relevant, especially if they are being skimmed out.

Finally, this would be relevent information only for the one skimmer tested, even if set up with replicates and controls. i.e. How good and how variable that brand of skimmer is in removing x compounds. I really am not interested in testing every possibly skimmer on the market to see which one is most effective in removing compounds x, y, z. I am interested in what skimmers remove and if there are differences in what they remove in various systems.
>>>Did I ask you to test every skimmer? Am I asking for efficiency? I don't think so. Most analysis of skimmate to date has been very basic. For me, if a skimmer can only remove a certain type of organics I might decide it isn't worth using. As far as I can tell siphoning works a hell of a lot better than skimming.

But, thanks - seriously - for the thoughts and interest. Your ideas could be tested, but would require some very deep pockets and/or a whole lot of donations, and a lot of time and labor from more than one person.

>>>Thanks for the comments. I feel my suggestion may have been seen by you as more of a critique. Wasn't intended that way. Since I have pulled my skimmer offline I may actually test this myself. I would welcome any suggestions if you have any.

Benj

RE: Preliminary look at skimmate

Eric Borneman — Thu, 22 Mar 2007 21:14:47 GMT

Several things:

1. You consider these experiments, and an experiment begins with a hypothesis. What is the hypothesis of your proposed experiments? I don't see that there is one.

2. What I am doing, at this point, are not experiments per se. They are analyses of samples. Now, I can do tests on them and do regressions and correlations with various factors. But, they aren't experiments.

>>Experiment 1:

Make a tank with just saltwater freshly madeup. Add known weight of pellet food or flake food(something dry with no water).<<

All food has water in it, so it would need to be baked to dry off water. How do you know there aren't organics in the seawater mix? Let's assume there aren't.

>> Use powerhead for circulation, seal tank,<<

Why seal the tank - to prevent airborne dust and debris?

>>add hepa filter on skimmer air intake.<<

A HEPA filter on the intake??? Wow. I don't have a HEPA filter for a skimmer

>> Skim until no visible food is in water, collect waste at multiple intervals and check dry weight.<<

Problem 1. Is removal of food a beneficial role of skimmers? I thought food was supposed to be eaten. Anyway, the idea here is removal of a particulate or organic material.
Problem 2. This requires multiple replicates and a control. The control would be just the plain seawater. Then, this means multiple skimmers of the same type, and I have already shown that two identical skimmers do not perform equally on the same or different tanks.

>.Then check CNP or protein concentration of tank water vs skimmate.<<

OK, this would show what is removed versus what remains. Of course, I'm already doing that with the various tanks.

>>Experiment 2:

Take tank water from a reef system (has bacteria and algae) add one mature fish. Run with skimmer for at least 1 week adding known quantities of food. Repeat above experiment (run skimmer until poop is gone).<<

This makes no sense. Why the fish? How do you measure remaining poop or other waste? How do you measure uptake by bacteria and algae? You would have to do counts and also all the issues as above.

Finally, this would be relevent information only for the one skimmer tested, even if set up with replicates and controls. i.e. How good and how variable that brand of skimmer is in removing x compounds. I really am not interested in testing every possibly skimmer on the market to see which one is most effective in removing compounds x, y, z. I am interested in what skimmers remove and if there are differences in what they remove in various systems.

But, thanks - seriously - for the thoughts and interest. Your ideas could be tested, but would require some very deep pockets and/or a whole lot of donations, and a lot of time and labor from more than one person.

RE: Preliminary look at skimmate

Warlan — Thu, 22 Mar 2007 20:24:43 GMT

Was directed to this thread from another forum. Very interesting stuff. I'm not sure if this would answer your question, but I was wondering why you haven't considered doing the following:

Experiment 1:

Make a tank with just saltwater freshly madeup. Add known weight of pellet food or flake food(something dry with no water). Use powerhead for circulation, seal tank, add hepa filter on skimmer air intake. Skim until no visible food is in water, collect waste at multiple intervals and check dry weight. Then check CNP or protein concentration of tank water vs skimmate.

Experiment 2:

Take tank water from a reef system (has bacteria and algae) add one mature fish. Run with skimmer for at least 1 week adding known quantities of food. Repeat above experiment (run skimmer until poop is gone).

This could be easily expanded to running with or without ozone.

Am I missing something? I would try this if the only spare skimmer I had wasn't a Sea Clone. I'm not entirely convinced it would pull anything out...

I'll save comments for what you are currently doing when the article comes out. Looking forward to it!

RE: Preliminary look at skimmate

Kent E — Wed, 21 Mar 2007 20:32:41 GMT

Eric Borneman (3/21/2007)

...freezer is filled with unsavory things.... ...and although most rocks don't smell bad, some primates do! As we found out in Borneo, though, orangutans don't smell, even with spilt milk all over them....

Wow, our lives are very, very different

RE: Preliminary look at skimmate

Eric Borneman — Wed, 21 Mar 2007 12:52:23 GMT

Not a word and I am pretty good at cleaning up such messes but out freezer is filled with unsavory things. She doesn't mind having a mad scientist at home, but then as a geology/anthropology major she understands science pretty well, and although most rocks don't smell bad, some primates do! As we found out in Borneo, though, orangutans don't smell, even with spilt milk all over them.

RE: Preliminary look at skimmate

jtremblay — Wed, 21 Mar 2007 09:46:54 GMT

I hopeyou did this in the lab or else your wife must bea saint

Wives of academics generally are

Jason

RE: Preliminary look at skimmate

Marie1 — Tue, 20 Mar 2007 15:09:48 GMT

It was brown, frothy, and had a white bacterial mat floating on the surface. Far fouler than any skimmate or skimmate mud has ever smelled. I had to remove it from the room and bleach the container. So, skimmate (no matter how foul we think it is) is mild compared to this concoction which, in itself, is nothing we don't have/put in our tanks.

I hope you did this in the lab or else your wife must be a saint