Recirculating skimmer vs. needlewheel?

[bronck83]

What's the difference? Advantage/disadvantages?

[LoneStar]

Well most recirculating skimmers are needlewheel skimmers. They both use the same 'type' of needle wheel pump to produce the air bubbles. The standard needlewheel skimmer (I.E. Euroreef or ASM) use a needlewheel pump to pump water into the skimmer tube.

A recirculating skimmer works a little differently. Most are feed through gravity (from a drain line from a overflow) or can be feed by a seperate feeder pump. Once the water is inserted into the skimmer tube, a needlewheel pump mounted to the side of the tube takes the water, injects bubbles into the water and then re-enters the skimmer tube. More expensive recirculating skimmers will use multiple needlewheel pumps to give you those fine, tiny bubbles.

Typically a recirculating needlewheel skimmer will cost you more.

[LoneStar]

A standard needlwheel skimmer design:
Water is pumped through the needlewheel pump, enters the chamber, then exits through the riser tube. The riser tube will adjust the height of the bubbles/water mixture allowing you the skim 'wetter' or 'dry'
http://www.mops.ca/skus/ps/PSAS-G.jpg


A standard recirculating needlwheel skimmer:
The water enters through a bulkhead on the skimmer tube/body. The side mounted needlwheel skimmer adds air bubbles to the body, allowing more surface area for the proteins to attach. Having a pump that recirculates over and over, allows for better nutrient export. Again, you have a riser tube to adjust the water level inside the tube/body.
http://www.saltycritter.com/images/pics/euroreef-with-ehiem.jpg

[thesponge]

LS that is a fantasic post with great pics thanks for the info

[BA]

great explanation!