Power heads how big and how many?

Ok I am putting together a 80 gal tank that is 3ft X 2ft X 2ft. I will be running a mag 9.5 return pump for the sump. I was wondering how many power heads I would need to use and how big. Where would the best place to place them.

 

I would start out with 2 K3's in the top front corners facing each other and see how the flow looks. Then go from there. Place the return in a rear corner shooting across the rear top of the tank. You want surface agitation also.

 

i have 2 k3 and 1 k4 3 mj1200 and my main pump flow in my 75.

i think a good flow is at least a 20x turn over of the tank volume

 

Also depends on what kind of corals you plan on keeping.

 

thats why i say at least a 20x turnover that will be good flow for lps and softies and if you want to get into SPS than it will not be that much to jump up the flow more

 

Where do you point the power heads in the tank.

 

You will want to point most of them upwards so that they create a ripple in the water's surface. You may also want one or two of them lower in the tank to prevent detritus and crap from settling on the sand and behind the rocks.

 

Another way to place your powerheads is so that the waterflow creates a GYRE. This is done in the best manner so the the general flow of the water is circular, with the surface water heading into your overflow. It is best for nutrient export, you also want to randomize the flow, which replicates the ebb and flow of wave action in the ocean.

IMO placing powerheads about halfway down the back pane of glass one toward each end of the tank(or more) aimed in the same area of the front pane is a great way to achieve this. The lower you can place them the better in my opinion, as long as you can make them look good and not kick up the sand.