How do you determine what is low, medium, and high flow in a tank?

[Daniel@R2R]

We've all heard that different corals need different rates of flow...but determining what that ACTUALLY is seems pretty arbitrary.

How do you figure this out? Do you just look at the corals and see how much turbulence they demonstrate? Is it about tank turnover rates? How do you decide?

Btw, a new innovation needs to be something we can use to measure gph flow at spots inside the tank (similar to how a PAR meter works but for flow). LOL Not sure that's even possible, but it would be useful. Can that be the next tech innovation??

 

[AdamNC]

I look at the polyps on both SPS and LPS. The SPS needs chaotic flow in all directions if possible or at least a side to side flow and the LPS needs just a gentle side to side flow. I tend to put my LPS on the sides and bottom of the tank and the SPS either in direct flow or off centered by a few inches. If on SPS I see polyps not growing I’ll move the power head slightly. If on LPS I see the skeleton or it’s not opening I’ll move the power head slightly. If neither are fixed in their place then I’ll move the coral.