Protein skimmer modification, what is it?

[kettlecorn]

First, can someone explain to me in layman's terms how a protein skimmer works? (Generally) I understand the purpose and somewhat how but not in detail which makes it more confusing.
The water from the tank goes into the skimmer (or drawn in) and then is pushed UP (with an air pump or something) and it goes up to the top where there is a collection up. And i'm lost. Why does it foam? etc.

Secondly, i just got a tank to start my reef tank! It is a RSM 130. The previous owner has done a modification to the skimmer but i really didn't understand very well what it is that he did. Other than the fact that he is a professional reef care and aquarium specialist as a living, and that he considered the stock skimmer as garbage, I don't know what he did to it or how it runs. Therefore, I don't know how to set up my own tank at the moment or what replacement parts I need.

I believe the top diagram will show you how the RSM skimmer works:
http://www.redseafish.com/redseamax/Red_Sea_MAX_specs.html

From what icould understand, he put in these tubes with airstone at the end and said it would foam like crazy and works a hundred times better than the stock setup. He said I would have to take an airpump and look the two airhoses into the setup and it would cause air to blow out of the airstones and cause foaming. Does this mean I do not need to run the turbo water pump that comes with the stock protein skimmer....? Or is this mod just for the colllection cup and I need to run both?
Pretty confused here.
:hmm3:

[Octoshark]

You should still have to use the pump on the skimmer since that is what sucks the water into the skimmer. By adding those air stones you are creating more bubbles, thats all. So you hook up the tubes with the air stones on them to an external air pump. An air pump is just something like this: http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=12738

You plug the air tube into that pump and it will pump air out of the air stones to create extra bubbles.

And to explain the science behind the skimmer as simple as possible, it basically works like this: matter sticks to the bubbles as the bubbles rise to the top and pop in the collection cup. When those bubbles pop, the matter that was stuck to them is left behind in your collection cup and you have successfully removed the matter from your tank. It is actually a pretty simple concept (the actual detailed science of how/why it does that may be more complicated but all you need to know is that matter sticks to the bubbles and rises up with them).

[Octoshark]

Also, I cant tell exactly how this guy modified the skimmer based on your description alone, but one thing I would definitely want to look into is the effect of these additional air stones to create more bubbles. If you have a massive amount of bubbles then it may cause the skimmer to be prone to overflowing. I dont want to worry you, but depending upon the design that could possibly be an area of concern.

[kettlecorn]

Sharp and clean. The explanation that is. :)
Thanks a lot, i understand. Yeah so I'm going to go ahead and disassemble most of it, including the protein skimmer and see exactly how he went ahead and did this thing. I might snap some pictures in case anyone else is interested in how this mod performs. For all i know, i'm sitting on a goldmine. haha
He was a very nice and honest guy from what i could tell and gave me an air pump as well. I bought new airstones at $3 a pop and some new air hoses.