how does a protein skimmer work?

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copi

Aquarium Advice Freak
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How does a protein skimmer work?

I understand the concept of organic waste sticking to the surface of the bubbles and being removed from the water before the enter the nitrogen cycle, but...

As I'm looking at my skimmer, it is basically a plastic tube... the bubbles rise up the tube as the watter travels down, there is a frothy foam from the bubbles at the top of the column of water, then empty plastic tube that goes up into the collection cup. How does the waste get up into the collection cup if the bubbles burst below the cup?

I installed the skimmer according to the instructions (the water level up to a certain line and the foam going up to a certain line). If the foam was allowed to go up into the cup (this makes sense to me if that is where the waste goes), the water would overflow on the floor.

I hope my question is clear. Thanks.
 
I'm not a physics expert however, the viscosity should keep the bubbles from bursting.
Think of it this way, the proteins are more solid than water therefore they form a balloon around the air. Another example, soap is thicker than water so it is harder to burst a bubble made of soap than that of water. Got it.. :?
 
How long has the tank and skimmer been running? Skimmers will not pull anything out until there is some source of organics. There will be bubbles but they wont be stable and will pop before they flow into the cup. Some skimmers also take some time to 'break' in.

My tanks been running for 3 weeks. When there was just water in the tank the skimmer(Aqua C EV180) pulled out nothing. When I dumped in the sand it helped pull out some silt. When I added the LR and during the Ammonia spike it pulled out ALOT of stuff but the waste wasn't very dark. Now that I'm into the Nitrite/Nitrate portion of the cycle I'm getting a very dark(coffee) colored waste.
 
Perhaps I don't understand... the instructions on my skimmer were to install as follows:

1) Adjust the skimmer so that the tank water came up to line "A"
2) Adjust the foam so that it came up to line "B" (above line "A," obviously).

Then, above the foam is empty plastic tube -- so how does the waste make it up into the collection cup if I'm supposed to adjust the foam to stop 2 inches below the cup?

I just want to be sure that I've set it up right... I'm not at all sure what I'm doing!

Thanks!
 
You've got it right. DOCs will increase the surface tention of the bubbles and cause them to survive longer & longer until they are pushed over the top and into your collection cup. For wet skimmate put the foam at 1.5" below the top and for dry skimmate put it lower. 2" is a good starting point.

Any coating still on the skimmer will break the surface tension of the bubbles so the skimmer won't work wonderful until that coating is dissolved (break-in period).
 
Basically you have it setup correctly. Now let it run a while and you'll see how the foam will begin to build up past line 'B', eventually falling into the collection cup.

You still didn't answer how new this tank is, and whether there's any livestock. A cycled tank with no fish will produce little skimmate. A cycled tank with a full stocking will have plenty to skim out.
 
Thanks for the advice - I do see that the skimmer has collected some brown liquid in the cup... I never saw the bubbles rise up in the tube, but they must have!

I didn't answer the questions about my tank because I am actually embarrased by some of the choices I've made in setting up -- apparantly I got some bad advice and am now stuck in an unfavorable situation. For example, the guy at the LFS told me "people cycle tanks with damsels," but the people on this board have given me something of a rough time about putting fish into a tank that hasn't cycled yet. To answer your question, I have a 29 gal tank with 2 damsels that has been up for a couple weeks. The protein skimmer has been in the water for about 24 hours now, and it is collecting waste so it appears to be installed correctly.

Thanks again, I'm sure I'll have a zillion more questions in the coming days.
 
I think you just need to allow for the proper breakin period for your skimmer. It is not uncommon for it to run for a couple of weeks before you start collecting anything. How they work...In the ocean you have waves that create surf. This causes the water to churn and O2 is mixed or whipped into the water. If you have ever been to the ocean and noticed a layer of foam on the beach or rocks you are seeing natural skimming. Your skimmer is creating the same effect in your tank, its artificial surf. DOC like protein bind with the bubbles and are taken out of circulation. This is the simple way it was explained to me. HTH...Lando
 
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