I think two Kessil 360s would be great on your tank but that is a pretty significant investment. I would still keep your 150s on. I know a guy with a 72g mostly SPS
tank that uses two Kessil 360s on that size tank. As you likely know, the 360s are all adjustable between blue and white light whereas the early 150s are not. As far as flow, I have two MP 40s and two sicce voyagers on my 220g, which together with the system pump flow produces plenty of flow. Have you considered the new maxspect gyre instead of another mp40? I've been considering replacing the two sicces with one of those.
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