Why wavemakers are better than unidirectional flow...

[acroman]

Check out these videos on mass-transfer. The first one is with water going straight at the colony. you can see how much "stuff" gets transfered in and out. The second video shows wave action. Theres about 10 times the mass transfer with waves....translating to reef tanks, this means more nutrients being taken up by the corals, and more superoxides and other wastes removed.

http://www.aslo.org/lo/toc/vol_51/issue_2/1134a1.html

 

[Anonymous]

Eric made a short comment above it in reefkeeping.com. There is nothing "shocking" about the conclusion, since the effect of wave and in particular, turbulent flow, on boundary layer and mass transfer dynamic is pretty much common knowledge among the oceanographic/limnologic as well as fluid dynamic communities. There are numerous articles in a periodical called Coral Reefs about these studies, as well as other oceanographic literatures.

The video looks very weird due to the use of LIF (laser induced flourescence) technique, and the coral is a dead skeleton, among other unrealistic senerios. The rate of mass transfer is not easily obtained from such experiment, as the authors stated. As comparsion, a more "realistic" experiment was conducted by Baird et al in Coral Reefs, (2003) 23:386-396 on an article titled Mass-transfer-limited nitrate uptake on a coral reef flat, Warraber Island, Torres Strait, Australia.

 

[acroman]

i agree there is nothing shocking, but i thought the video showed a decent difference, using a cool technique.
again thanks for the reference, ill be sure to check it out.

 

[Len]

Nice vids. Thanks for sharing.

 

[Anonymous]

I want to get that kind of wave flow in my seahorse/seagrass tank, but I don't want to add another pump because of the heat and noise ... and it can't be too strong a current, either, cuz the horses are wee. I have a SCWD on the return, but it's like a trickle (and I'm using a Mag 9.5!).

 

[Anonymous]

now while I'm not knocking multi-directional flow to me it looks as if the "smoke" while moving more so than the unidirectional flow doesn't look like it's leaving the coral. So that if that were some toxic blob, sure it'll be moving around more but it'd stay right over the coral.

 

[Anonymous]

As mentioned, the rate of the mass transfer is not easily deducted from the video, but the 'dynamic' of it. It relies on both wave *and* linear flow to carries the smoke away, but for the generation of the video, there is no linear flow in the wave experiment due to the complexity.