Over Skimming

[DrDave88]

This is a common question, but bare with me.
I intend to have a FOWLR in a 110gal with undertank refgium connected to a sump, with a skimmer in the sump.
I am having trouble understanding what skimmer to buy, counter current or venturi? I have been researching to the fullest, but am not sure what the true difference is and what suits me the best. I am worried about getting too many small bubbles in my sump, so I am planning ahead of time to prevent myself from buying one that will cause the most trouble. I understand that skimming takes out the "toxins," for lack of better terminology, but how does one over-skim?

So my questions are:
What is the difference between types of skimmers?
What is the best method of skimming to prevent micro bubbles to enter the sump?
How does one over skim?

In response to a recent thread about new reefers and old ones - Suck it up old timers, give us new kids the help we need, before we start to ask for help on what to do with that 18-inch panther grouper in our 20 gal tank.

Ps - how does LR move? J/k

 

[Enkidu]

If you baffle your sump and have the skimmer (either the skimmer itself if its an in-sump model, or the skimmer outlet if not) in a different section than your return pump you shouldn't have any microbubbles.

The concept of "overskimming" is a touchy subject for some of us reefers. Some would say that you can't really overskim. Others would say that if you make the water too clean it can adversely affect you tank inhabitants. With a FOWLR I would not worry about overskimming, and I would get a pretty big skimmer at that. Maybe one of the biggest Aqua-C models or Bullet models. The problem I have with alot of the Bullet skimmers (beckett injected) is that they require a monster pump to run them. Those big pumps draw alot of juice, and if you're living in an area that has seen significantly increased electricity costs (which is everywhere I think), that should play a role in your decision. Of course, if you've got piles of cash at your disposal you probably won't worry about it. Its your decision.

 

[DrDave88]

Still looking for more advise about the skimmers...

I also wonder how much do you pay for your pump useage per month, or your total system, say between a 100 and 200 gal tank? just wondering...

dr

 

[Cruiser]

DrDave88

As an "oldtimer" in the hobby, I will give it my best shot.....

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote

I am having trouble understanding what skimmer to buy, counter current or venturi?

Counter current is describing the different directions the water & air are moving in realtionship to each other inside the skimmer reaction chamber. Water is pumped in the top of the skimmer and exits near the bottom. The air enters the skimmer at the bottom and rises to the top & out through the cup - counter current.

The "venturi" effect is used to generate the air & water mixture injected into the skimmers. Venturi consists of a tube with a short, narrow center section and widened, tapered ends, so that a fluid (tank effluent water) flowing through the center section at a higher velocity than through an end section creates a pressure differential which draws (ambient or ozone) air & mixing into the water stream before it enters the skimmer reaction chamber.

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>So my questions are:
What is the difference between types of skimmers?
What is the best method of skimming to prevent micro bubbles to enter the sump?<hr></blockquote>

The only major difference between current skimmer models is the way the air / water stream is generated. "Beckett / aerator" type skimmers are really just using a special, well designed "venturi" to produce the air / water stream. Beckett / Aerator skimmers require high velocity water to work effeciently. Regular venturi skimmers function the same but are justing using a smaller scale & old fashion fluid venturi methods.

Current skimmers either use venturi (some older air pump / limewood airstones still used & effecient) to generate air / water stream, which is then injected (better word?)into the skimmer reaction chamber, where the skimmed water is drawn from the bottom, and the rising air / foam is drawn out into the collection cup.

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote

How does one over skim?

Personally, in my opinion you can't over-skim a tank. Two well tuned skimmers are very effect way to maintain high water quality.

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote

Ps - how does LR move? J/k

Well trained "PET ROCK"

Good luck with skimmer decision

 

[Ben1]

I believe when people talk about overskimming they are worried about trace element removal. Not only does your skimmer reduce organics but it slightly reduces trace elements with a monster skimmer it could be enough to make a difference. I just posted a tread on "which is the best skimmer" it had lots of usefull info. Search under my member # and read that tread it should help you a bit.

I just set up my Euro-reef CS8-3 a week ago and am still judging it. I feel so far it was the best skimmer for me. It has the longest dwell time, uses a small pump, is very easy to clean and adjust, uses a nice union so almost no clearence is needed for cup removal, and has an 8" body. So far it is pulling out a thick black skimmate which was my goal.

 

[danmhippo]

Over skimming, (if ever possible), can be corrected with regular monthly water changes.