Skimming faster vs. skimming cleaner.

[dascharisma]

I am interested in knowing if different skimmers will give cleaner water.

I assume that a larger skimmer with a big water volume and a high flow rate will skim a greater volume of water in the same time that a small skimmer will. For a large system with a big bioload it makes sense to try to skim the water as rapidly as possible. After all, there should be plenty of nutrients being constantly produced to keep the skimmer busy.

I am interested in knowing if skimmers skim to a greater degree of cleanliness. If 2 different skimmers were set up on identical tanks with zero nutrient import, both skimmers would eventually reach a threshold where they will no longer take anything out of the water. I know that many factors determine how quickly each skimmer reaches that point. My question is if all skimmers have the same skimming threshold. Will every skimmer eventually skim to the same level of cleanliness, or are some skimmers able to make the water cleaner than others?

If different skimmers do clean the water to different degrees, does anyone know why this is? What variables influence this the most? Right now I have 2 different types of skimmer on my tank. The larger one does all the skimming. Is this just because it is able to process more water? Has the smaller skimmer just reached its threshold and the larger skimmer has a lower threshold?


Brad

 

[jackson6745]

Let me start by saying that a skimmer will ALWAYS have something to pull out, even on the cleanest aquariums. No need for the hypothetical situation to confuse things

Skimmers will skim to a different degree based on the amount of air being injected and the contact time within the skimmer body. A skimmer that can produce more, tiny bubbles will foam better
and consequently remove more waste. A good skimmer will be filled with enough tiny bubbles that you shouldn't be able to see through the skimmer body.

 

[shelburn61]

Some skimmers are able to make the water cleaner than others b/c the faster a skimmer is able to remove compounds the less time they have to degrade to the unskimmable nutrient molecules we are always battling.

For the most part it comes down to the amount of air to water contact area the skimmer can produce over a given period of time. i.e. You want as much bubble surface-area (so smaller bubbles are better) coming into contact with as much nutrient-laden water as possible, but then you still have to take into account the contact time of a bubble with a given volume of water b/c it takes minutes before some molecules are able to attach to a bubble to be skimmed out. Then you also have to worry about whether the skimmables will actually make it into the collection cup before redissolving. It's a very complicated balancing act b/c air flow, water flow, chamber volume, riser size, etc. all have different effects on the various factors. There have been some good discussions of this in the DIY forum. Check Randy's skimming article as well.

 

[rkl303]

Small bubbles are also more stable so they are less likely to pop as they try and make it to the collection cup.

 

[NoSchwag]

Re: Skimming faster vs. skimming cleaner.

<a href=showthread.php?s=&postid=6582928#post6582928 target=_blank>Originally posted</a> by dascharisma
My question is if all skimmers have the same skimming threshold. Will every skimmer eventually skim to the same level of cleanliness, or are some skimmers able to make the water cleaner than others?

From my understanding...

If you have a skimmer that is designed to skim protiens (dwell time) out of the water then you are fighting an uphill battle from the start. It will take longer to clean the water and by that time it's too late because there are already more protiens to skim out (fish poop, ect..).

If you have a skimmer designed to skim particles out of the tank, you are removing it before it breaks down, resulting in cleaner water.

So yes, it's logical that a particle skimmer will keep the water cleaner than a protien skimmer assuming you get the crap to the skimmer. I'm not sure how or if this applies to your situation. Is one of your skimmers skimming "wetter" than the other?

 

[shelburn61]

Dwell time shouldn't have any affect on the ability to skim particles, unless the particles are allowed to settle elsewhere. Dwell time is determined by skimmer height, volume, and flow pattern while wetness of skimmate is just water level and neck shape. Independent of each other IMO. I'll take long dwell time with wet skimmate any day to get particles and proteins.

 

[NoSchwag]

Is it possible to skim wet and still have a long dwell time? I thought dwell time was the amount of time that water was in contact with the bubbles??

Right now I skim wet and pump about 1000g/hr thru my skimmer, my dwell time seems to be about 2 seconds.

 

[merlock116]

get a couple and have them go head to head. put them both in a container with just tank water, no livestock.