What is truly needed?

[SchrutesReefs]

Thanks! How many/what size would you recommend for a 40 breeder? What locations in the tank give you the best results?

That would depend on your coral placement imo. Some people have flow directed at their corals if necessary, as well as flow behind their rock under the return flow to help clear detritus from the “dead flow” area. I don’t keep sps so my flow is on the mid-range size. I have a 20g IM Nuvo and I am currently using 1 AI Nero 3. I have mine set in the middle of the tank on the side wall. The bottom flow hits my zoas, and the top of the flow hits the too of my aquascape. This setup works well for me, but your return pump could be better than mine and your flow would be different.