IMO, I would like all the polyps on a coral to move every few seconds or so ... but I do want polyp extension. It doesn't need to blow around wildly or violently ... it just needs to move a little.
So much is dependent on the tank, the aquascaping, and the corals. IMO/IME, you don't need 100x flow for a tank of frags, though when you start to get softball sized colonies grown out - you do need to make sure water flow isn't cut off by their new size. And that with an open aquascaping, lesser #'s can get the job done.
Staghorns, plating Montipora and others can really affect the flow overall, and may require flow changes to cope with. I don't see a way of getting around periodic changes - given we're unknowing of how corals will exactly grow out, how they will cumulatively change your perfectly set-up flow to imperfect.
But IMO, it seems that very high flow is something the tank grows into needing.
..Right now, I have the return and a Tunze 6080..Thinking of adding some more flow though..maybe a SQWD powered by a Mag12 or something..But i noticed that what blows tissue off is strong, constant current, if it alternates from strong to slow and so on, it will be ok..lesson learned.
Is that a 150g tank or a 150g washing machine?
