Sound OFF: It's all about that FLOW that FLOW that FLOW!

[MnFish1]

Water flow at the great barrier reef. 9 months south, 3 months north. http://www.mrstevennewman.com/geo/GBR/Hydrological.htm

Source: http://www.marine.csiro.au/LeafletsFolder/37eac/

So over hundreds of miles it seems like the flow is laminar. Australia is huge - the little circles there would suggest that mostly the flow is laminar in most areas. Or am I misunderstanding your point

 

[PicassoDan]

Flow all going in the same average direction does not mean laminar. Laminar flow is a very specific type of flow where all of the fluid particles move along the same streamlines. Imagine a bunch of lines of traffic all flowing nicely, and no one switching lanes.
This guy has a pretty good "real-world" description of flow regimes:
https://www.princeton.edu/~asmits/Bicycle_web/transition.html

 

[vetteguy53081]

I use a combo of both but tend to lean towards gyre type movement.

 

[rockskimmerflow]

Laminar IMO. Nothing wrong with chaotic, just feel that laminar flow that shifts over long intervals (15 mins +) is a bit more advantageous for stony coral development.

 

[Brad Vaughn]

I recently had to store a bunch of acros while setting up a new tank. My goal was to keep them alive while the new tank cycled. They are getting a lot less flow than before and less chaotic. The results are pretty amazing. They are thriving. That was unexpected. I have an 89" tank. Going for circular flow with two smaller powerheads, one high one lower on the front left side, then one larger powerhead on the back right side, high.

 

[Brew12]

"You keep using that word. I don't think it means what you think it means..."

If you have anything above a slight movement of water in your tank, it's really all turbulent flow. Nothing in front of a powerhead can be accurately called laminar. I realize it's just terminology, but in this case it's bad terminology, and I wish we could get away from it.

Yup, you are absolutely correct. But, it seems to be the commonly accepted term to use in the hobby to describe relatively linear flow as opposed to having the flow from different powerheads pointed into each other.

Do you have a better term we could use to replace it with?

 

[PicassoDan]

Hmmm, maybe organized flow vs. disorganized?
I do realize I'm being a bit semantic...

 

[sghera64]

Me too but which is better ?

Variety is the spice of life. . . on the land and in the air and sea. (Wo)Man cannot subsist on bread alone, and corals can't subsist on laminar flow alone.

 

[Bob Escher]

I would say my MP10 are laminar

 

[hatfielj]

I am convinced that the best flow for any tank is having 2 opposing gyres at the long ends of each side, alternating their flow...1 on, 1 off, switch, repeat. This provides a pattern similar to waves coming in, then waves going out. I've used every type of flow device imaginable and this has been the best I've found yet.

 

[Brew12]

Hmmm, maybe organized flow vs. disorganized?
I do realize I'm being a bit semantic...

I get it. In the engineering world, words have a very precise and important meaning. I feel the same way with the term "cycled" for a new tank. A tank is never "cycled" as the process is continues. But.. as much as I'd like to make the term go away, its what is used.

In this case, I just don't see a better option that wouldn't cause additional confusion. Especially since scientists use the term when studying coral reefs.