How do skimmers work?

[surjer]

Something I noticed that really just boggles me is that if you stick your hand in the tank for a minute the skimmer will stop skimming. Then it takes it a great deal of time to get started again. Why does this happen?

 

[macman7010]

Surjer,

That is odd that you skimmer stops working when you place your hand in the tank. Are you sure that something else is not causing the skimmer to stop? I have, in all my years keeping saltwater aquariums, never noticed a protien skimmer that stopped skimming when my hand was in the tank.

Varius water additives, (Calcium, Iodine, Etc.) can cause the skimmer to skim more then usual, often times just skimming water; while others can slow or stop the production of micro bubbles, though just placing your hand in the tank should not stop the skimmer. The only thing that I can think would effect your protien skimmer if your hand is in the tank would be an oil or residue on your hand, other then that the skimmer should run just fine.

 

[surjer]

I remember somewhere on nanoreef.com they were saying the oils from your hand could stop it but I really dont understand how it would effect the skimmer itself. I guess I am confused as to how the skimmer reacts with water. It makes sense that the oils from my hand will get into the water and therefore change the water composition but I wouldnt think it would have an effect on the skimmer. You would think the skimmer would just bubble away no matter what.. weird.. lol

 

[Devilishturtles]

A skimmer works by blasting the water with tons and tons of microbubbles. Those bubbles trap DOC's and other nasties "on" them, and carry them out of the water column, leaving behind more "pure" water. That's a loose description however.

Perhaps oils impede the formation of bubbles... I'm not sure. I've never noticed it when I stick my hands in my tanks. Try washing your hands (and rinsing well) before you put your hands in the tank. See if it still does it.

I can't imagine that small of an amount would have any effect... but who knows.

 

[roka64]

About the only reason I can think of, is the water displacement from your hand/arm in the water is effecting the skimmer's water level. Take a look at that and see.

 

[MT79]

Oil absolutley will affect skimmer performance. Many times "cheaper" skimmers will stop skimming all together after putting your hands in the tank or after feedings. I noticed the same thing w/ a seaclone skimmer. I would only have to touch the tip of a finger in the tank, and that was it for a day. No skimmate. It impedes the bond that forms between the surface of the bubbles and the DOC's.

 

[roka64]

Really, thanks for the info! Another question, do they actually pull out fish waste, thus eliminating the need for a filter (along with 1.5-2Lbs of rock per gallon)?

 

[surjer]

I am also curious about that roka. I have noticed my skimate is actually a light brownish color. Looks like tea almost. I have no fish in my tank tho...

 

[MT79]

Well, they will pull out DOC's before they are converted to NH3, nitrite, and NO3 essentially reducing the bio-load and nutrient levels of the tank, improving water quality. You'll still need a sufficient bio-filter. Also LR has many benefits in reefs besides providing surface area for bacteria. Exactly what is pulled out by skimmers is not really well documented AFAIK, although I will say reefs do better with them than without. I think that is a pretty well known fact. What a good skimmer will do for a tank is worth every penny. FWIW GAC makes a great addition to a skimmer b/c it removes some things a skimmer most likely will not. They compliment each other very nicely. Eric Borneman has an interesting thread where he is examining skimmate from different tanks/skimmers to see what it contains and the amounts. I have not checked it in a while, but here is a link- http://forum.marinedepot.com/Topic52254-9-1.aspx

 

[roka64]

Sweet! Thanks for the explination on the skimmer!