Skimmer Types

[Pixjann]

Im setting up a Rio 180 as a Reef tank and im looking for a skimmer that will sit under the tank . I dont have the room for a hang on skimmer ,and the tank is not drilled for a sump . So if anyone can recomend a skimmer to go under the tank i would greatly appreciate it

 

[superman]

Im setting up a Rio 180 as a Reef tank and im looking for a skimmer that will sit under the tank . I dont have the room for a hang on skimmer ,and the tank is not drilled for a sump . So if anyone can recomend a skimmer to go under the tank i would greatly appreciate it

When putting a skimmer under a tank you will need to attach a sump. All skimmers that sit under the tank need to be coupled with a sump. So your choices are to either get the tank drilled (VERY worth it!) Or get a skimmer that hangs on the back of the tank.

 

[steelhealr]

I agree with Superman.....a HOB. In the UK (is that where you're from?) Deltec is supposed to be a popular skimmer. SH

 

[Pixjann]

The problem with drilling is that its not a new tank and glass becomes prone to cracking as it ages As to a hang on i dont have the space However a friend of mine has turned the plastic trim on a Jewel tank into an overflow by drilling it maybe ill have to go down that route and then fit a sump even though the cupboard is a bit tight for space

 

[andywg]

Drilling older glass is no problem. I had a 20 year old 10mm glass tank drilled no probs.

From the reading I have been doing it appears that to gain ideal skimming you are better off with an air pump skimmer so that you can increase the amount of bubbles independant of the flow through the skimmer.

 

[superman]

Drilling older glass is no problem. I had a 20 year old 10mm glass tank drilled no probs.

From the reading I have been doing it appears that to gain ideal skimming you are better off with an air pump skimmer so that you can increase the amount of bubbles independant of the flow through the skimmer.

Most people do not go with an air driven skimmer, they are not consistant enough, they are only as good as the air stone used inside them, air stones clog slowly over time, which would mean that you would have to be constantly tweaking the air input to the skimmer. Pain in the butt if you ask me.

 

[andywg]

But, you can control the air a lot better.

If you look at the ideal skimming equation worked out by Peter Escobal in his book Aquatic Systems Engineering; you should have the volume of the tank pass through the skimmer once every 1 1/3 hours (80 minutes). Most venturi design skimmers will go far quicker than this.

You ideally want to have the volume of the tank skimmed every 8-12 hours (so te whole tank is skimmed 2-3 times per day).

Using the formula

Total system volume/skimmer flow rate (gph) x 9.2 (purety coefficient that will yield 99.99%processed water) = hours until processed.

So in a 150 gph tank you need to feed around 115 gph water to the skimmer. On top of that you need a lot of air going in for bubbles to enable skimming (some proteins need to be in contact with bubbles for up to 2 minutes to "cling on". I can't see that happening on a huge flow rate. That is why air pump skimmers are the ideal solution.

you do have to change the air stones fairly frequently, but that is no great hastle, and it will help you keep the skimmer spotless B)

For a real technological understanding, read this thread on another forum

Skimming Principles

(Nav, I don't like to post to other forums, but the technoligical discussion is of great interest, and I can't plagurise much more than I already have done in the above. If this is not ok and the link gets removed, PM me for the address.)

 

[superman]

But, you can control the air a lot better.

If you look at the ideal skimming equation worked out by Peter Escobal in his book Aquatic Systems Engineering; you should have the volume of the tank pass through the skimmer once every 1 1/3 hours (80 minutes). Most venturi design skimmers will go far quicker than this.

You ideally want to have the volume of the tank skimmed every 8-12 hours (so te whole tank is skimmed 2-3 times per day).

Using the formula

Total system volume/skimmer flow rate (gph) x 9.2 (purety coefficient that will yield 99.99%processed water) = hours until processed.

So in a 150 gph tank you need to feed around 115 gph water to the skimmer. On top of that you need a lot of air going in for bubbles to enable skimming (some proteins need to be in contact with bubbles for up to 2 minutes to "cling on". I can't see that happening on a huge flow rate. That is why air pump skimmers are the ideal solution.

you do have to change the air stones fairly frequently, but that is no great hastle, and it will help you keep the skimmer spotless B)

For a real technological understanding, read this thread on another forum

Skimming Principles

(Nav, I don't like to post to other forums, but the technoligical discussion is of great interest, and I can't plagurise much more than I already have done in the above. If this is not ok and the link gets removed, PM me for the address.)

We're getting off topic a bit, but oh well, it may benefit Pixjann in the end.

Such a generalized number of gph through a skimmer is simply misleading, differences in effectiveness between needlewheels, air stone, becket, injection...etc to generalize such a thing as GPH through a skimmer is way to misleading. If you are looking at the most effective type of skimming, most people go with a recirculating needlewheel skimmer you get a lot of dwell time for proteins to "stick" to them, and without the frustration of a super tall finnicky air stone skimmer.
Back to the question at hand...
I LOVE my ASM skimmer, which is a brand that makes clones of Euroreef skimmers (they get around the patent by using clear PVC instead of acrylic) I would personally recommend a needlewheel skimmer of a reputable brand, maybe even a recirculating depending on what kind of money you want to throw into this important filtration system piece.

 

[Pixjann]

thanks for the info , i think im going to get the tank drilled ( im replacing the front glass anyway ) so while the tanks in bits i'll get it drilled the i'll either build a sump to suit the cabinet or get an aqua medic combined skimmer and filter unit

 

[superman]

IMO, I would avoid the all in one units, they are usually lacking in quality when it comes to the skimmer. I would save my money and just go with a tub or aquarium as your sump, and then invest in a good in sump skimmer that is highly regarded.