DOC Test for Skimmer Performance?
DOC Test for Skimmer Performance?
I agree that freshwater skimmers tend to be tall with modest air intake. This can be discerned from the specifications of the Schuran freshwater skimmers (
http://www.schuran.com/freshwater/abschaeumer_e.html). There must be a lesson here that saltwater skimmers can adopt.
I think that one measure of a skimmer is its ability to skim relatively soluble dissolved organic compounds (DOC). It is easy for any skimmer to skim insoluble particulate matter. As we move down the solubility scale to DOC’s such as Gelbstoff (yellowing compounds), skimming gets harder. Are you aware of any skimmers that can remove Gelbstoff?
I believe that there may be a simple way to test the DOC solubility level to which a skimmer can filter. A controlled method of comparing two skimmers will be to take seawater or water from a water change and place it into two tanks. Place a skimmer on each tank with a small circulation pump and measure the DOC concentration in both tanks periodically.
A test for a single DOC type may be sufficient because the ability to skim a DOC of a specific solubility also implies the ability to skim DOC’s with less solubility. Suppose the Salifert Organics test can measure the concentration of a DOC with solubility K. A skimmer that can skim that DOC can also skim DOC’s with solubility k < K. If skimmer A can lower the concentration of that DOC more than skimmer B, then skimmer A is superior to B.
Of course, if the Salifert Organics kit measures a DOC that any skimmer can skim or a DOC than no skimmer can skim, it will be hard to differentiate the skimmers. Hopefully, the test kit will measure a DOC type that is moderately challenging to skim and will not be too easily degraded by bacteria.
Such a test will be superior to:
(1) Placing a Remora in cesspool and claiming that it pulls more gunk than a Bubble King in the Monterey Bay aquarium.
(2) Using a wet skimmer to demonstrate that it can drain a tank faster than a dry skimmer.