How much flow for a reef tank

I noticed when the pumps are off at feeding time, my corals start to get
bigger and look better. I even turned off my 2 power heads to leave my tank
completely quit and calm.

However, I know flow is necessary to oxigenate the water and to keep the
waste moving to disposal via skimmer/filter.

My flowerpot coral get huge when the flow is very little to none, otherwise
they shrink completely.

My current set up is 2 return power heads from the sump and a couple of
power heads flowing toward the front wall.
I just removed one flowing sideways because my torch coral didn't like it
much.

Any advice on how to manage flow quantity and direction?

Also, any Alveopora flow requierements?

TIA

Ruben