[tmz]

Originally Posted by Dan_P

Sure, what you state is true, flowing water moves things, and skimmer flow moves upwards, but all this is not really relevant in discussing how skimmers operate, that is, how they concentrate material and how things end up in the collection cup. If by chance a particle is caught in the flow, it could end up in the collection cup. And if this chance occurrence is what you are talking about, then OK!

That's what I said in post #10. Upward flow is part of what skimmers do;so is aeration btw:


The water a protein skimmer pushes to the cup will pass along some small amounts of dissolved nutrients like a very small water change will as Jon noted.

The rising flow action in the skimmer will also push along bits of this and that algae detritus bacteria etc.

However, the foam fractionation function( the actual "skimming") relies on the attraction of organic molecules to water and their repulsion from it. Amphipathic molecules like proteins and others with bi-polarity are pulled toward the water on one side and repelled by it on the other. These ampipathic molecules are most susceptible to removal via skimming as they get cling to the air and water surface there at the same time and get trapped between the bubbles.


I have no idea why you chose to contradict it in absolute terms.



The movement of particulate matter via flow is relevant to the OPs question about nutrient removal and a part ,albeit perhaps a small one, of the way skimmers operate. Some of the bits of material moved along by the flow to the cup would otherwise decay or dissolve in the tank and do also account for some of the content of the skimmate.