A general (and I mean very general) rule of thumb is that the polyps on your SPS colonies should have a decent movement every 3 seconds (by which I mean they "twitch" "flick", whatever you call it.. with the current). I'd say turn it down so that this was your minimum. The intensity of flow changes depending on how and where you have the unit mounted. Does it blow as the front glass? Does it go end to end? Do you have a lot of rock in the way? So it's easiest to use this as a gauge for the minimum then tweak it up of down depending on the behavior of the SPS.
|