study on skimmer performance
 

So basically all skimmers will remove the max amount of 30-35% organics butv the rate at which it does this will vary depending on the size of skimmer?

Great article, i guess putting all money in high end skimmer is a waste :-)

Unless your using other factors to justify the money spent.....like how many times you need to throw the skimmer off your deck before it starts to work properly :razz:

Good article, but didn't account for enough break-in for the high end skimmers in my opinion. After a full clean it takes 2-3days for mine to get going, and higher end ones take even longer in many cases. They gave it 24 hours, so that will benefit the skimmers with the least amount of surface.

But a good study, good that we have a way of measuring skimmer performance, and interesting to see the results.

skimmer
 

yes,
the size also doesn't matter because the skimmers are on 24/7 the will skim but some faster and some slower.

Unless you have fish that constantly poop more than normal

In many cases high-end means high-end pump. All these things blow bubbles but after dealing with the crap pump on my swc I'd rather have a solid pump getting me my 30% removal than my crap pump which I need to babysit to make sure it's even ON lol.

In a closed system with no TOC generation, a skimmer will only remove 30% and bigger skimmers will remove it faster, however, in the manner in which we run them (ie. continuously) the bigger skimmer WILL WORK BETTER because it will remove the labile TOC faster than the others. For example, if the rate of removal of the labile TOC is greater than the rate of labile TOC generation there will be no accumulation; however, if your skimmer is undersized you won't be removing the labile TOC as fast as they are generated and you will have TOC build up.

The rate of removal becomes even more important if you are running carbon dosing systems, such as vodka dosing, where you are converting the refractory TOC (that is otherwise not removed by a skimmer) to biomass in the form of bacteria. Since you would then be able to remove all of the TOC, not just the labile TOC, the equations they use become skewed. In this situation you will need an oversized skimmer to keep up with removal demands as removable products increase from 30% to anywhere from 65% to 80% (not all TOC is converted to biomass since the bacteria produce CO2 during metabolism, assuming all TOC is consumed by bacterial metabolism).

I wouldn't say that this article says spending a ton on a high end skimmer is a waste but (break issues described above aside) it makes the case for oversizing your skimmer. They didn't show suspended solid removal (ie. bacteria removal) in these tests at all. The high end skimmers that produce smaller bubbles in high quantities will remove organic suspended solids much faster than a POS skimmer will. So again, since we are running in a continuous manner, rate and size become important.

Thus endth the first class of ScubaSteve's water filtration tutorial. Please leave your apple for the teacher on your way out and don't let the door hit you on the @ss as you leave:wink:

Till next week's class:biggrin:

So a skimmer with better pump that creates finer bubbles is better? But what about the footprint and height of the skimmer? Would that create a huge difference?

What i got out of the article is BUBBLE KINGS RULE :twised: :wink::wink:

Does it it make a difference? It does, yes. But that's what I mean by "bigger" skimmer. The effectiveness of a skimmer is determined not only by the size and quantity of bubbles produced in the skimmer but also by the residence time of water in the skimmer.

The longer a particular parcel of water spends in contact with the bubble phase, the more organics are attached to the bubbles (thus increasing removal). The more bubble surface area, the more removal. The greater the separation of organic-laden bubbles from the water, the reduced chance of re-entrainment (thus increased removal). All of these have an effect on the skimmer performance. The "removal rate" that they present in the paper is an aggregate rate that takes into all of these effects.

And it IS possible to calculate the theoretical removal rate of the skimmer and how it changes with all of the different design parameters (maybe this will be something that I'll teach). But the number one parameter that will have the greatest effect is the skimmer volume. The bigger the volume, the bigger the throughput and the greater the residence time. A tiny skimmer with a huge pump that makes tons of bubbles isn't going to do much because the water won't stay in the skimmer long enough for it to matter (and you'll just fill your sump with bubbles).

We call this selective information uptake. My girlfriend says I have this problem too.... "blah blah blah... sex... blah blah blah blah":razz:

Buying a bubble king is like paying labron when you could be paying dwayne wade

kimmer
 

IN your opinion what are the top skimmers ?

So would an oversize skimmer body with a smaller pump (still big enough for the water volume) work better because water would spend more time in the skimmer?

if the size of the bubbles and the quantity of the bubbles were also there ....im thinking so anyways lol

Hehehehe... you're asking the wrong guy for that one. See, I'm a grad student... I'm too poor to play the "Best Skimmer On The Market" game :razz: Personally I like Vertex skimmers for bang for the buck but would like to try the SWC skimmers (or other cone skimmer) because they tend to be more efficient for a given volume (and have a reduced foot print with the bottom or internally mounted pumps). So for guys like me who have very small, cramped sumps, reduced space is a blessing. That being said, build quality and pump quality would be more of a concern for me than the fanciness of the skimmer.

try Bubble Magnus, it rules

No, because residence time, diameter and air volume all have effects on skimmer operation. Increasing the skimmer height increases the contact time, whereas the skimmer diameter controls the bombardment rate (which is the number of times a parcel of water bumps into a bubble... in a sense, bubble density). The bombardment rate is ultimately the the limiting factor to how much a skimmer pulls out of the water column. If you had a super wide body to the skimmer you'll just have a bunch of bubbles in the center and not much else going on. You need the narrow diameter to create the bubble storm of death that we use in our skimmers to get effective contact between the bubbles and water.

The airflow rate is determined as a function of skimmer diameter, length, bombardment rate and absolute contact time, which are all functions of the amount of water flow through the unit itself. So when you are designing a skimmer, you select a throughput rate (which is specified as a function of the tank volume you are trying to skim) and then you design the other parameters around this. And to complicate all of this, how you design all of those parameters depends on what bubble contact pattern you are using, what type of air injection your are using, whether you shred the bubbles, etc... There is a definite optimal zone for parameters.

i saw a guy on kijiji selling a diy skimmer made out of one of those blue 5 gallon water jugs.