Airstone or Beckett

[titus]

Hello,

Just curious. How many of you actually would like to use an air driven 6' tall counter current skimmer over a Beckett or ETSS skimmer?

Titus

[Shadetree]

Beckett hands down for me. Size limitations prevent me from owning an air atone skimmer worth anything. Besides there are a few things that aren't done yet with the beckett skimmers that I would like to try.

Scott

PS My thoughts are also based on the size of my tank, if it was much smaller an airstone skimmer might be a less power hungry piece of equipment

[Doug]

Titus, I would love a 6ft counter current. Trying to find one that works as advertised, is another thing. As my tank is behind a wall, its perfect for my use. I would love to dump my sump and have a stand up skimmer behind.

I have tried several types and none have even come close to my Euroreef, with most being a supreme pain to control. Also I used the biggest advertised normal type airpump, without going to the large type stores use, and still could not drive the airstones enough. The guys I know that use the mon the boards, drive them with huge airpumps.

[Dale D]

That's exactly what I have been thinking of putting on my system.

Getting an air pump that was big enough would be the biggest problem I think. Without it costing a fortune.

How about a CC venturi or recirculating CC venturi design.

If you are ever in Big Al's in Burnaby get Grant to show you the skimmer he built for his hugh new display tank. It's a recirculating CC venturi skimmer and it is 13 feet tall. images/smiles/icon_eek.gif

Dale

[ 15 August 2001: Message edited by: Dale D ]

[titus]

Hello guys,

Well the cons for air driven skimmers are size, difficulty of adjustments, and power consumption. However, I believe given the proper equipment, a patience to adjust it properly, air driven skimmers can out perform Becketts or ETSS.

And yes I was thinking about the piston type air pumps. Not those ones you plug into the wall with. images/smiles/icon_biggrin.gif

There are a few reasons why I came to this conclusion. When I still used to build skimmers, I paid very close attention to the surface turbulence of Beckett skimmers, and non-Beckett skimmers. I found that Beckett requires a very high flow rate to achieve a good bubble density. This high flow rate unfortunately results in a higher surface turbulence.

This turbulence is caused by 2 factors:
1) Most high aeration skimmers are feed offset. This mean the air/water mix is fed next to the riser column. And some bubbles accumulate in size by trapping at the top plate. When these bubbles finally move over to the riser column, they rise up too fast because of its size.

2) Further because the feed is offset, you always see one side of the riser column causing a compromise when adjusting air intake. In the case of the PM Bullet 2, bubbles with larger size rises faster and more violently on the side where the Bullet injector is.

Note that if the feed can be brought directly to the center of the riser column then the above 2 problems should go away when properly designed.

Finally, there is a problem with bubbles returned. Because of the compactness of these skimmers and the use of a vertical baffle, large amount of bubbles are being returned. So there really isn't much counter current action as most of the bubbles that go downward towards the drain actually got drained out of the skimmer.

Solution?
1) Do what the Aerofoamer does by injecting directly into the riser column. This solve all 3 of the above problems. And add a nice counter current action.

2) Do what I used to do with the CS-2 horizontal baffle. This solve also all 3 of the above problems. The also add a very nice counter current action. This happens when the water turns 180 degree around, right below the riser column.

I think the more I iterate the design, or the more I think about it, the Aerofoamer approach of feeding directly into the riser column is the way to go. However, I know of a different point in the riser column where I can feed to give better counter current action.

Titus

[Doug]

Or, use a Euroreef, which solves all those problems and provides just as good skimming.

The only drawback would be the amount of tank water passed through the skimmer in a certain period of time, as compared with a larger pump driven beckett.

[titus]

Hello Doug,

I haven't see a Euroreef skimmer in operation. I don't know whether it has the same amount of bubble density as a Beckett or air stone skimmer.

As far as I know, airstone still gives the least bubble size with the most bubble density. Then comes Beckett. Then venturi.

Titus

[Doug]

First, I use the largest Eheim pump on mine. It packs the 6in.- 20in. tube, with tiny bubbles, so packed, it looks like solid white pvc.

I also agree om the cc. Its believed still to be the best, IF, the proper equipment is used. The great thing about my Euroreef though, is thats its fool proof, for people like me images/smiles/icon_eek.gif

I have been thinking about the purchase of a Tunze 3130, to go inside the tank, to eliminate the sump.

[frag]

Just my oppenion on the air driven skimmers. They area pain to keep the stones from cloging! I had a HSA 1000, it was a nightmare to clean. Sold it and got am Aerofoamer. Best thing I ever did. Easy to clean and Kick Butt.
It comes apart easy and is easy to clean! I saw one of the older generation Aerofoamer and is no comparison to the new ones with the orings. No tubulence as talked about here. New to this B. Board. Tom

[titus]

Hello Tom,

That's right. Because the Aerofoamers inject water directly into the acrylic tube, there's no chance for bubbles to collect and build up. So no turbulence.

I agree with the maintenance issue with airstone. However, speaking strictly on a performance side, you can't beat the bubble size and the fact you can have CONTROL over the water and air ratio.

Titus