[quote author=islandcreation link=topic=5727.msg71706#msg71706 date=1230413071]
[quote author=GreshamH link=topic=5727.msg71689#msg71689 date=1230407112]
Wave Boxes on their own don't move much water, they only create a small standing wave. Most use other PH's for their flow and the WB for the "motion".
FWIW "turnover" is a useless calculation, just like watts per gallon.
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Then how would one know wether or not they have the right flow? With lighting you can test for PAR so I can understand that watts rule is false. But how can one test for the correct flow? My only test would be visual movement of polyps extension. Besides watching surface agitation and making sure there are no dead spots via detritus build up.
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Flow isn't like lighting where you only have a few things effecting how much light hits a tank. With flow everything in your tank effects it so what works best in your tank may not even be remotely enough for another tank. This is one reason why "turn over" is useless. How you arrange your rocks, how big they are, how porous they are, where you direct your flow, what pump you use, how many corals you have, how large they are, sand bed/no sand bed, etc... all effect how much flow is in a tank. Giving a number is rather meaningless due to all those factors. Flow is measured in cm/s. Take a bubble passing by, or debris, and count how fast it travels across a known measurement.
[quote author=Dyngoe link=topic=5727.msg71710#msg71710 date=1230421804]
We had a presentation on water movement and the guy (sorry forgot his name) basically said that corals will increase growth with increased flow, PERIOD. So, basically you try to add as much flow as possible until it starts to "hurt" the corals. For example my mushrooms would shrivel and die at the flow I have going over my SPS. One way you can measure flow is by adding bubbles to your tank and watching them. I just add an airstone before my return pump and see what happens in the tank.[/quote]
Jake Adams was his name
He mentioned several methods to measure flow in aquaria, bubbles, debris, even oatmeal (not in a set up aquarium though
)[. Cm per second is the most common measurement. Several people (including myself) have tried to make a cheap flow measuring device for aquaria but no one has put one out as of yet.