The Mathematical Proof of Skimming

dallasg

dallasg

Controversial Reefer, but knowledgeable!
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So while doing some research for my possible masters in Maths i came across this :)

Recent design innovations like bubble plates, conical sides, or pinwheel impellers do not seem to impact significantly on either rate of TOC removal or amount of TOC removed, at least for the skimmers tested. Thus, skimmer manufacturer claims about enhanced organic removal capabilities should be met with skepticism in the absence of compelling and quantitative TOC removal data.
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Feature Article: Further Studies on Protein Skimmer Performance — Advanced Aquarist | Aquarist Magazine and Blog

It is tough reading but here are the highlights:

The study measured two aspects of skimmer performance:
(1) how fast the skimmer removes organic matter from salt water, and
(2) the amount of organic contaminants removed relative to the total amount present in the tank water.

Two types of water were prepared for skimming tests:
(1) Bovine Serum Albumin (1.33 gm, 96% pure from Sigma Chemical Company) was dissolved in 35 gallons of 35 ppt freshly prepared saltwater (Coralife brand salt mix).
(2) Reef tank water was removed at 60 ± 15 min after tank feeding (tank skimmer off).

Two analytic techniques were used:
(1) The BSA-containing samples were analyzed using a Pierce Micro BCA Protein assay kit with the addition of a brief sample centrifugation step prior to UV/VIS analysis.
(2) The reef tank water samples were analyzed on a Shimadzu 5000 TOC Analyzer.

Four skimmers were tested:
(1) EuroReef CS80 needlewheel
(2) ETSS Evolution 500 downdraft
(3) Precision Marine ES100 venturi
(4) Precision Marine AP624 airstone

The test results show that all 4 skimmers were similar in performance:
(1) All 4 skimmers removed organic compounds at similar rates.
(2) All 4 skimmers removed over 80% of the serum in the BSA water.
(3) All 4 skimmers removed only 20% to 30% of the Total Organic Compounds (TOC) in the reef tank water.

None of the skimmers were able to remove much beyond 30% of the TOC in the reef tank water. Hypothesized is whether we are approaching the limits of foam fractionation.

tell me what you think :)
 
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Interresting read.

I do agree personally - If skimmers removed 100% TOC we would not need water changes, only additives to replenish used compounds like ca, mg etc.

I think bubble plates and skimmer shapes etc. did make them more efficient, but nothing is as efficient as nature, no matter how hard we try and replicate :p
 
hehe, never too much maths :)
 
Jeann1 said:
I think bubble plates and skimmer shapes etc. did make them more efficient, but nothing is as efficient as nature, no matter how hard we try and replicate :p
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to be honest and reading the article a 2nd time, its food for advertising, the average contact time needed for protein to be removed from water is abour 2m32s if i remember correctly, so slow contact time is needed to the bubbles, not blasting them with 1000000000L pumps :)
 
dallasg said:
not blasting them with 1000000000L pumps
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unless its a becket!!!! but its fun to swith on your skimmer and watch the that meter they had on TV go to RED and watch the neigbourhood brace for loadshedding....
 
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dallasg said:
So while doing some research for my possible masters in Maths i came across this :)

Feature Article: Further Studies on Protein Skimmer Performance — Advanced Aquarist | Aquarist Magazine and Blog

It is tough reading but here are the highlights:

The study measured two aspects of skimmer performance:
(1) how fast the skimmer removes organic matter from salt water, and
(2) the amount of organic contaminants removed relative to the total amount present in the tank water.

Two types of water were prepared for skimming tests:
(1) Bovine Serum Albumin (1.33 gm, 96% pure from Sigma Chemical Company) was dissolved in 35 gallons of 35 ppt freshly prepared saltwater (Coralife brand salt mix).
(2) Reef tank water was removed at 60 ± 15 min after tank feeding (tank skimmer off).

Two analytic techniques were used:
(1) The BSA-containing samples were analyzed using a Pierce Micro BCA Protein assay kit with the addition of a brief sample centrifugation step prior to UV/VIS analysis.
(2) The reef tank water samples were analyzed on a Shimadzu 5000 TOC Analyzer.

Four skimmers were tested:
(1) EuroReef CS80 needlewheel
(2) ETSS Evolution 500 downdraft
(3) Precision Marine ES100 venturi
(4) Precision Marine AP624 airstone

The test results show that all 4 skimmers were similar in performance:
(1) All 4 skimmers removed organic compounds at similar rates.
(2) All 4 skimmers removed over 80% of the serum in the BSA water.
(3) All 4 skimmers removed only 20% to 30% of the Total Organic Compounds (TOC) in the reef tank water.

None of the skimmers were able to remove much beyond 30% of the TOC in the reef tank water. Hypothesized is whether we are approaching the limits of foam fractionation.

tell me what you think :)
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Dallas there are other things you can do at night boet :lol:

459b said:
I think its too much maths for a friday!!!

definatley.. i am now overloaded..

Very interesting read. Would like to see what would happen if they fed continually instrad of measuring a once off feed.
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definatley.. i am now overloaded..

Jeann1 said:
Interresting read.

I do agree personally - If skimmers removed 100% TOC we would not need water changes, only additives to replenish used compounds like ca, mg etc.

I think bubble plates and skimmer shapes etc. did make them more efficient, but nothing is as efficient as nature, no matter how hard we try and replicate :p
Click to expand...


dallasg said:
hehe, never too much maths :)
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dallasg said:
to be honest and reading the article a 2nd time, its food for advertising, the average contact time needed for protein to be removed from water is abour 2m32s if i remember correctly, so slow contact time is needed to the bubbles, not blasting them with 1000000000L pumps :)
Click to expand...

maybe the right test hasnt been found in order to properly asses the removals? but that is just food for thoought.. i will definatley say that skimmers have become smaller and yet more effiecient.. that trend alone should to a degree be taken into account here... (possibly proving the point)

blackghostknife said:
HI Dallasg

Interesting read, but I think you just fried my brain.:goofy:
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time for a :peroni:
 
dude! i am cycling my tank, nothing else to do at home :)

but on the jol there is plenty
 
That was a good article
 
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