I'm interested in knowing what exactly am I removing from my marine tank when I use a protein skimmer. I know it's to remove DOCs, but what exactly does that include?

I guess more importantly, I'm interested in knowing if my ferts such as Fe, I, etc.. are being removed by skimming. When I examine the contents of the skimmer, it has a distinctive green pea soup look, with suspended particles that look like microalgae (likely from cleaning windows, etc.)

Does anyone have any insight into the chemistry of skimming?

Thanks,

RAS

Rather than going into it:

What is Skimming? by Randy Holmes-Farley - Reefkeeping.com

Then you can think about it and ask if you have more questions.
Randy's articles on RC are pretty good.

Regards,
Tom Barr

Thanks Tom, exactly what i was looking for!

RAS

I have twice pulled the plug on the skimmer only to turn it back on.

The first time was after the plants had started establishing themselves and were growing nicely. After I switched off the skimmer for a day I noticed the plants were looking a bit raggy and there was a lot of particles in the water column. I turned on the skimmer and things looked much better. This surprised me a bit and I reasoned the skimmer may have been providing good gas exchange.

I eventually got round to buying an internal filter and set it up in the sump to replace the skimmer. I positioned it so there was plenty surface agitation and let it run for a week. Again, the tank had lost a bit of its sparkle and I once more resorted to the skimmer.

Now it could be that the skimmer is removing traces but since they are cheap I don't bother about it. The only additives I add to the tank are CaNO3 and an Fe supplement. I still suspect that the skimmer is providing excellent aeration and since I keep seahorses, I have a relatively low water turnover rate. What's more, I can go a month without emptying it.

I tend to think it stabilizes the CO2/O2.
I never get any skimmate in the planted systems and it's been years..........


Regards,
Tom Barr

I think we're talking two different things here:

A protein skimmer, a filtration system usually used in marine tanks to remove organics...

and

A surface skimmer, a simple device that skims the water surface (or an overflow which accomplishes the same thing).

Sorry, I just re-read reiverix's thread and realized my post was rubbish. You can't unplug surface skimmers...

Ignore me please...

Do you actually get skimmate in freshwater?

No skimmate from a fresh tank.

Do you know why?

What does salt do to the polarity of water?

Regards,
Tom Barr