"Natural Filtration"

[mmcguffi]

It's times like this that I wish I still had access to journals...

 

I have access to journals but I wouldnt even know where to begin in terms of what journal, author, title, etc. If you guys have any suggestions to locating a good paper or actually find a paper you want downloaded, there's a 90% chance I can get it.

[bitts]

The Question That should perhaps be addressed though. Is weather or not skimming should be considered, to be part of a natural methodology tank.

 

There is a strong argument for it in either direction. Since it does recreate the natural actions of the surface fetch. How ever it is a peace of equipment & therefore could be considered, by some, to be inherently unnatural. On my own system with net volume of 30 gallons, putting it right at the limit of being a nano. I never do water changes, feed much more than any of the info I've read tells me to, & so on. Mostly because of things that many consider to be "unnatural", such as vodka, skimming, dosing. All of which I started doing in the pursuit of a more natural & biologically based system.

[bitts]

I have access to journals but I wouldnt even know where to begin in terms of what journal, author, title, etc. If you guys have any suggestions to locating a good paper or actually find a paper you want downloaded, there's a 90% chance I can get it.

 

 

Oh really Mmm... I know there's got to be some.

 

How about anything by Stephen Spotte. From there I'll have to think.

[mmcguffi]

After a quick search this is all I could find by Stephen Spotte that is relevant.

 

Fish and invertebrate culture; water management in closed systems.

Author(s): Spotte, Stephen H

Title(s): Fish and invertebrate culture; water management in closed systems.

Other Title(s): Water management in closed systems

Publisher: New York, Wiley-Interscience [c1970]

Description: xiv, 145 p. illus.

Language: English

ISBN: 9780471817604, 0471817600

LCCN: 74-130433

MeSH: Ecology*, Fisheries/instrumentation*, Fishes*, Invertebrates*, Water*

Notes: Bibliography: p. 121-131.

NLM ID: 1251624 [book]

 

However, it's not available for digital download, only in book format tucked away deep within the depths of one of the libraries. So if you guys REALLY want it, I may be able to track it down after some of my more pressing work clears up

 

Note: it also seems this was published in 1970, not exactly up to date

[bensanders]

Publisher: New York, Wiley-Interscience [c1970]

 

Hmm, one look at that date and I question it's relevancy..

[bitts]

The reason I immediately thought of him. Was his work "Captive Saltwater Fish" had quite a bit of information in it on skimmers. But he also did more scientific work.

[mmcguffi]

Captive Seawater Fishes (1992)

 

http://books.google.com/books?id=tMeuQ4v_m...tte&f=false

[bitts]

Thats the one. Old, but still very good.

[bitts]

But returning to the main topic at hand. It really comes down to an understanding off the microbial ecology of ocean water. How our tanks relate to it, such as how the tanks system alters said ecology, how the fluctuation in nutrient levels effect the ecology & so on. From there & really only once that is understood, can it be determined if skimming is beneficial or not. Depending on whether or not the nutrients both organic & trace pulled would be a necessary component of the ecology. But of course we need to know the exact nutrients being pulled from the water column, to be able to judge the effect.

 

The main thing going for skimmers are that they seem to work & bubbles are cheap. But so do water changes. So We may never know anything beyond this. At least not in any authoritative way.

[blasterman]

Everybody talks about skimmers being effective at beating nitrate to the punch, but many of us don't have nitrate problems to begin with. Skimmers are just as effective as DOC removers, and unlike carbon and other mechanical / chemical removal means they actually take junk out of the water.

 

Considering the turbulance at the surface of the ocean skimmers are not the 'artificial' gadget they would seem to be. Obviously people have never seen the deitrus stuck in the foam at a lake or sea shore.

 

There is no 'natural' way to keep an artificial reef tank in your house.

 

You can certainly keep a succesfull reef tank without a skimmer (I've done so for years), but all my experience points to the fact that a good one reduces the needs for water changes. Also, I'm increasingly miffed at the complete and utter lack of really good, HOB skimmers optimized for smaller tanks.

[jdl]

i have read through this entire thread, and correct me if im wrong please. also this will be severely dumbed down, sorry.

 

heavy tank feeding = increased nutrients or organics, skimming will help remove said nutrients and or organincs, while also depleting some needed elements. more frequent water changes or dosing will help compensate for depleted elements.

 

for a small system, that is heavily fed, a skimmer would make things a little "easier" as far as maintenence. instead of large water changes, one could just do more frequent smaller changes.

 

obviously this is not the norm for a small tank, but is this on the right track?

[Urchinhead]

Nothing about the way bubbles act in seawater has changed in the last 10 years. Our understanding of it has, but I am hard pressed to find any evidence that skimmers were ever shown to remove trace elements. I think it is one of those suspicions or hunches that got repeated enough that people started saying it as if it was a fact.

 

Frankly I can't see how they would remove trace elements... Correct me if I am wrong but the purpose of the skimmer is to create foam fractionating which traps hydrophobic ions of which CaCO3, Ca, and I (calcium carbonate, calcium, iodine) are not. As I remember it they are actually hydrophilic. At least the ones we use for coral growth that is.

 

However N, P, C, etc are hydrophobic and thus are removed from the water via the foam fractionating.

 

Ergo how would the addition of a skimmer have a detrimental impact of a tank of any size other than perhaps in a small tank compared to the size/efficiency of the skimmer creating an ultra low nutrient environment where fatty acids and the beneficial levels of N/P/C are so low/non-existent that the zooxanthellae found in the corals as well as the "biological" filtration components effectively starve...?

[mmcguffi]

Frankly I can't see how they would remove trace elements... Correct me if I am wrong but the purpose of the skimmer is to create foam fractionating which traps hydrophobic ions of which CaCO3, Ca, and I (calcium carbonate, calcium, iodine) are not. As I remember it they are actually hydrophilic. At least the ones we use for coral growth that is.

 

However N, P, C, etc are hydrophobic and thus are removed from the water via the foam fractionating.

 

Ergo how would the addition of a skimmer have a detrimental impact of a tank of any size other than perhaps in a small tank compared to the size/efficiency of the skimmer creating an ultra low nutrient environment where fatty acids and the beneficial levels of N/P/C are so low/non-existent that the zooxanthellae found in the corals as well as the "biological" filtration components effectively starve...

 

 

Ions by nature cannot be hydrophobic. All are hydrophilic. The specific organic compounds containing nitrogen, phosphate (phosphorus), and/or carbon are all highly dependent on stucture. I think the issue with removing these ions is the possibility that they are associating with organic compounds forming biometals and other weird things.

 

Also I have no idea what the "natural beneficial levels" of these organic compounds are but I assume they are very low. Im 95% sure that the zooxanthellae get the majority of their trace elements from their host, drawing the majority of their carbon from dissolved CO2 in the water. Im not sure where they get their N, P, or S but I can assume that feeding your tank would keep these levels in check even with a skimmer.

 

Soo Ive been doing a lot of thinking and my vote is that a properly sized skimmer for a nano would be beneficial to keeping stable levels as well as reducing excess waste that can easily plague small tanks.

 

This is all hypothetical though as I dont have long term expirence with running nano tanks with and without skimmers!

[Urchinhead]

Ions by nature cannot be hydrophobic. All are hydrophilic. The specific organic compounds containing nitrogen, phosphate (phosphorus), and/or carbon are all highly dependent on stucture. I think the issue with removing these ions is the possibility that they are associating with organic compounds forming biometals and other weird things.

 

Pardon me. You are right. I was thinking molecules when I said ions.

 

Also I have no idea what the "natural beneficial levels" of these organic compounds are but I assume they are very low. Im 95% sure that the zooxanthellae get the majority of their trace elements from their host, drawing the majority of their carbon from dissolved CO2 in the water. Im not sure where they get their N, P, or S but I can assume that feeding your tank would keep these levels in check even with a skimmer.

 

They are low relative to the goals we have regarding the corals we keep. The Zooxanthellae do require X amount of N and P for fuel actually but as you mention the levels are very low in our size tanks. Actually if I remember right the N and P are ultimately what turn corals brown since there is a greater amount of zooxanthellae reproduction and thus density due to the higher levels of nutrients available. Again if I remember right Zooxanthellae only get about 70% of their nutritional needs from photosynthesis.

 

Soo Ive been doing a lot of thinking and my vote is that a properly sized skimmer for a nano would be beneficial to keeping stable levels as well as reducing excess waste that can easily plague small tanks.

 

This is all hypothetical though as I dont have long term expirence with running nano tanks with and without skimmers!

 

Perhaps an interesting experiment? Wouldn't be too hard to run and or control. Two tanks one with skimmer one without. Allow buildup of N & P to X level in one and Y in the other using a colorimeter for accurate (relative) reading of the amounts in the water and see what occurs to a coral colony that is split into two pieces...

 

Any idea where one can go for grant money to do that kind of experiment? Reason I ask was I was kicking around doing a similar experiment with LED vs. T5 lighting and was thinking about where to go for grant funding...

[RayWhisperer]

Get ahold of Eric Borneman. Your method is more scientific than anything he's done.

[jeremai]

you guys are way overthinking this article, lol.

[wombat]

Frankly I can't see how they would remove trace elements... Correct me if I am wrong but the purpose of the skimmer is to create foam fractionating which traps hydrophobic ions of which CaCO3, Ca, and I (calcium carbonate, calcium, iodine) are not. As I remember it they are actually hydrophilic. At least the ones we use for coral growth that is.

 

You should definitely read the advancedaquarist link I posted on the first page. Dr. Feldman's skimmer removed a lot of CaCO3, MgCO3, and SiO2. It's possible that the skimmer is removing microorganisms (diatoms, coccolithophores) that concentrate these. It's also possible that it's concentrated from fish poo.

 

I hope to answer some of this confusion by throwing some skimmate under an SEM soon. Yahoo for fancy tools!

[HecticDialectics]

Any idea where one can go for grant money to do that kind of experiment? Reason I ask was I was kicking around doing a similar experiment with LED vs. T5 lighting and was thinking about where to go for grant funding...

 

I doubt many folks with lots of grant money are interested in coral growth in artificial systems

[HecticDialectics]

You should definitely read the advancedaquarist link I posted on the first page. Dr. Feldman's skimmer removed a lot of CaCO3, MgCO3, and SiO2. It's possible that the skimmer is removing microorganisms (diatoms, coccolithophores) that concentrate these. It's also possible that it's concentrated from fish poo.

 

I hope to answer some of this confusion by throwing some skimmate under an SEM soon. Yahoo for fancy tools!

 

I'd agree if you had said the article said skimmate was COMPOSED OF a decently high percentage of CaCO2, MgCO3, and SiO2, but it certainly doesn't state how the amount REMOVED compares to the amount left in water.

 

And this line should make everyone cringe, lol: "Any discrepancies can be easily explained by the numerical uncertainty introduced through all of the assumptions. That is, even with all of the assumptions and approximations cited in this analysis, the sum total of the mass works out to within 3% of "perfect". "

 

Perhaps an interesting experiment? Wouldn't be too hard to run and or control. Two tanks one with skimmer one without. Allow buildup of N & P to X level in one and Y in the other using a colorimeter for accurate (relative) reading of the amounts in the water and see what occurs to a coral colony that is split into two pieces...

 

http://www.springerlink.com/content/g2554037454q13wp/

[HecticDialectics]

I'd agree if you had said the article said skimmate was COMPOSED OF a decently high percentage of CaCO2, MgCO3, and SiO2, but it certainly doesn't state how the amount REMOVED compares to the amount left in water.

 

To further my point:

"Finally calcium can be bound to organic compounds. These organics can be natural (e.g. proteins and carbohydrates) or (un)intentionally added chemicals like EDTA, vitamin C, polygluconate, and polyphosphates (Holmes-Farley, 2002). The formed complexes may be discarded from the system via protein skimmers. At Burgers’ Ocean, Arnhem three protein skimmers on coral systems had a 8 to 12% higher calcium level in the discarded foam compared to the aquarium water after equalizing to the same salinity. These figures are much lower than found by Sondervan (2001) where the difference was 30%. Still the effect on the calcium concentration of the aquarium water will be neglectable, since only small quantities of solution will be discarded via a protein skimmer."

 

Advances in Coral Husbandry in Public Aquariums. Public Aquarium Husbandry Series, vol. 2. R.J. Leewis and M. Janse (eds.), pp. 133-142

© 2008

 

 

I also read the Sondervan article cited in the above. It discusses how calcium carbonate was lower in an invertebrate tank with a protein skimmer was less than calcium in their "mammoth system." What it failed to mention or consider was the increased uptake of calcium by the invertebrates in a smaller quantity of water than organisms consuming calcium in the other much larger tanks. That would explain the difference between a 10% and a 30% reduction.

 

Either way, having say 1 cup of skimmate a week on a larger aquarium, if the skimmate is EVEN as high as 30% calcium, the effect of the total calcium level in the tank wouldn't be effected in any great amount. Certainly nothing that water changes or basic supplementation wouldn't take care of. This is to be expected, of course, given the thousands upon thousands of people who USE protein skimmers not having to dose massive amounts of calcium in tanks not widely populated by calcium-consuming organisms.

[wombat]

I don't know exactly what you're trying to prove to me. The amount of CaCO3 removed by a skimmer from an entire system is clearly trivial. I think we agree on that and it is plainly obvious.

 

And this line should make everyone cringe, lol: "Any discrepancies can be easily explained by the numerical uncertainty introduced through all of the assumptions. That is, even with all of the assumptions and approximations cited in this analysis, the sum total of the mass works out..."

 

Why should it make us cringe? Even mass specs are not 100% accurate...

[wombat]

I'd agree if you had said the article said skimmate was COMPOSED OF a decently high percentage of CaCO2, MgCO3, and SiO2, but it certainly doesn't state how the amount REMOVED compares to the amount left in water.

 

Ok, I agree. I should have been less short. Perhaps "the skimmer concentrated CaCO3, MgCO3, and SiO2 at concentrations much greater than they are found in NSW."

 

For what it's worth the Si removed is significant in the way that you thought I meant.

[HecticDialectics]

Ok, I agree. I should have been less short. Perhaps "the skimmer concentrated CaCO3, MgCO3, and SiO2 at concentrations much greater than they are found in NSW."

 

For what it's worth the Si removed is significant in the way that you thought I meant.

 

 

Yup, we agree 98%. We certainly agree that urchin, et al. are wrong about how certain elements are not removed by skimming.

[wombat]

Yup. But to be fair, the Ca and CO3 are not being removed as Ca2+ and CO3--. The stuff removed by the skimmer is already insoluble. So a skimmer would affect the concentration of Ca and CO3 much like removing sand from your tank would. It's already precipitated out and not affecting the available concentration of either ion.

 

Long story short, skimmers are doing nothing bad. I just wanted to be pedantic about the details.

[Urchinhead]

I doubt many folks with lots of grant money are interested in coral growth in artificial systems

 

You would actually be surprised what's out there and for what.