The most important qualities you want in a skimmer


New member
I'm writting a research paper about the effectiveness of foam fractionation in an aquarium, and get some opinions on what the most important factors are in purchasing and running a protein skimmer.

So far I think I should include:
- Ease of maintenance
- Size
- Pump requirement(s)
- Noise
- Amount of disolved organics removed (duh...)
- Air to water contact time

What are some other important factors that I haven't thought of ?

Thanks !


New member
Excellent! thanks a lot. More I have the more I can write the better =)

Where can I purchase an air intake meter?


New member
Most of what's listed here goes under "amount of dissolved organics removed" -- contact time, bubble size, air intake, all of that.

For me, the factors are:
- Amount of dissolved organics removed
- Size
- Noise
- Maintenance (especially ease of cup removal)
- Reliability / build quality
- Internal or external
- Cost

I can't exactly prioritize this list. Many are "pass/fail", e.g. size (it either fits in my space or it doesn't). Cost is definitely a factor but I would rather pay more for higher quality and performance. Energy usage isn't that big of an issue -- most of that goes into lights, return pumps, chiller, heater, etc. If your skimmer is a big part of your total energy usage, you've got something very wrong!



In Memoriam
"effectiveness of foam fractionation in an aquarium"? What, like a quantitative performance study or something? Good luck on that, its nearly impossible to do because there are several design elements which are codependent and related, although not identical.

If that is what you are doing, then the list gets complicated, fast:

-airflow per cross sectional area of the neck
-neck height
-collection cup mechanisms (how best to direct the foam into the pot, as well as keep it clean)
-body height
-body diameter in relation to the combined turbulence & output of the air/water mixing mechanism/pump/etc.
-bubble diameter, method of bubble production
-interface method (counter current, co current, etc), distance, duration between water and air.
-shape of main body and reducer to neck
-turbulence reduction methods (bubble plates, elbows and splitters, etc)
-water throughput volume
-air throughput volume
-time/path that a bubble takes from input to the neck
-time/path that the water takes from input to the outlet
-chemistry of the water being cleaned (the maximum potential of any skimmer depends on the amount hydrophobic matter that it can deal with, as well as the salinity, and other factors which determine how well the skimmer will work regardless of the skimmer itself).

If this is the route you were thinking of going, I would suggest narrowing it down to comparing one or two principles... like height or chemistry... and going from there.

just dave

11th in '11
I read a lot of these in "in depth" skimmer posts and reviews and many are informative and most are entertaining but when it comes down to it all I care about are the following.

Can it remove a lot of schmutz ( Too technical?)
Ease of use and maintenance.
Reliability of pump and ease of acquiring a replacement.

I take manufacturers ratings and cut them in half and I would rather use two skimmers instead of one larger one.

I'm also glad the things I use and the animals I keep can't read.


In Memoriam
The 'output' of a skimmer, besides heavily depending on what there is to work with in the first place, can be defined in several ways though. There are several classes of proteins and hydrophobic substances, some good, some bad. Some skimmers can remove all of some, but none of another type. Some can remove a little bit of everything maybe, or alot of something else. Others may rely on extended exposure in the mixing chamber or in the main body to buffer the ORP, pH, or even oxygenation of the water, changing its chemistry. There are ways to make shorter skimmers perform like taller ones, and the time that a bubble spends exposed and interfaced to a protein can be compared at several different points... the time while bouyant in the water in the main body, or perhaps the time it is stacked in the neck and spends time draining as it rises in the foam head and into the collection cup. Many mfg's dont even know what may make their design work better than another, and in many ways they cant since they dont know how the end user will set up and adjust that product, or what it will be expected to do. The customer could decide to skim wet or dry, or to vary the input (if recirc/external) from 100gph to 1000gph, and all of these things will change the results. Its not a very exact science by any means. I think the rating system is flawed for sure though... and rating a skimmer based on tank volume isnt the best way, as a 500g with two fish in it wont come close to the waste output of a 100g with a dozen fish. Some skimmers with lower air throughputs can destroy the output of some with higher air throughputs because their design might be so much better otherwise, with cone shapes, bubble plates, extra height, etc. So there is not one exact method which gives the best results.

I was at the Shedd behind the scenes tour this saturday, and their RK2 skimmers are making them very unhappy. They are huge skimmers (a few feet in diameter, over 10' tall) with venturis and ozone going in, and their skimmate production sucks. I looked at the dwyer meter on the air intake, and it read only 100scfh!!! the skimmers were mostly just swirling some bubbles in alot of water. They had some other ones (smaller models, maybe 18" diameter and about 8' tall), that they just removed all together and decided to just do massive water changes instead. I felt bad, but I had to tell them that my next skimmer will only be 36-42" tall, use only about 85 watts, and make about 130-140 scfh of bubbles and skim the crap out of one of those RK2's most likely. I was like 'maybe you would like to try it?' or something because for all the things that those skimmers had going for them as far as the specs were concerned, their performance blew.


New member
Wow, thanks for all that info! that's even more than I had expected.
The purpose is for my senior year engineering project in high school. We had to pick a project that had as many engineering design and construction aspects as possible, and already having some background, I decided to design, construct, and test a DIY re-circulating skimmer modeling a Deltec or Euroreef.
Now for the paper I need to outline basicly "what makes a skimmer good" and mine being DIY i want to compare performance with cost.

It's somewhat of a cost analysis / manufacturing documentation / I needed a skimmer on my tank =)

Where can I buy an air intake meter? I can measure flow through the skimmer, but not air intake.

Thanks again !