Water Flow Question

Alot depends on what you are going to keep.

I like the flow so I can see the polyps on my corals are moving all the time.

Also good flow keeps all the waste suspended so it can be filtered out.

 

I believe the 10x turnover refers to the amount of flow you want going through your filter on a freshwater, or fish only tank. While that would be fine for many soft corals I think you should shoot for at least 20-30x plus your return pump for a mixed reef.
People that keep mainly sps I believe have much more. When websites list high, medium and low flow I take it as where you should put ithe coral in YOUR tank. Every tank will have areas of higher and lower flow.
I have about 4500 gph plus I'm probably pushing around 400gph through my return pump in my 110 gallon mixed reef and I seem to be able to find a spot for everything to do well.

I would shoot for 2x 900-1400 gph pumps in a 65. I'd like to hear what other have to say as well.

 

I had around 2000gph max in my biocube - figure it holds around 10g in the display for about 200x but not constant, only peak and now I run about half that max. In my 65 I have ~500gph sump return and a wp25 that peaks at 2000gph I think. I consider this medium flow and a bit under 40x turnover. Both those tanks have variable flow rate powerheads so that is the max they run.

 

i have 2 modded maxijet 900's on 1 end of my 75 gal and 1 modded maxijet 1200 on the other end of the tank and the return pump is a 1500gph that is throttled back a little and i have been making this work real well, i also have the needlepoint plastic around my mod kits to ward off the long ternticle nem i have in there when hes stretching out.

its working well for me.