Power Head Placement in 90 Gallon?

[salth2o]

Hi Group!
A friend is putting together a new 90 gallon Reef tank. Tank will startout with 40 lbs live rock and probably go up to 90-100. Misc Corals etc. Live sand and VHO light
The question is this: How many powerheads? Where would you place them? I have my opinion, but he would like others opinions as well.
I appreciate your time.

 

[hollywood85]

I have been told to turn the water over 10x/per hour.
90gal.x10=900gph. However many you want to buy to get that number. I have seven in my 90..... And boy, do the sps' love it!!!

 

[salth2o]

More thoughts? Positions?

 

[slick]

I have 3 maxi jet 1200's in my 90. 2 at the top on each end and 1 behind the rock wall near the bottom to keep stuff from setteling back there.

 

[phoenixrising]

I use three Maxi Jet 1200's with a Tsunami wave maker and also have quite a bit of flow from the return (GenX 1200GPH). The return is hooked to a Sea Swirl to further move the water. This is on my packed full 90 reef and everything in there (no SPS) is looking beautiful.
I have two powerheads on one side and one on the other. The sea swirl is in the corner so it sweeps the whole tank.

 

[jarre]

I have 2 Maxi 1200's and a Rio 800 in my 45. The 800 points behind the rock low in the tank. One of the Maxi's points facing the Rio half way up the tank and the other Maxi is above the RIO in the corner blowing diagonally across the tank.
I don't know of any dead spots and watch the flow all the time to ensure I don't have any.

 

[pyro383]

It also depends on what corals require, case in point is the sun coral likes alot of water movement but a gorgorian likes a gently sway. I just moved 1 of the powerheads to blow directly on the suncoral and it loves it, all polyps extend.