Powerhead placement

[squid row]

Is the purpose of the powerheads to create surface flow or movement of water throughout the water column?

I have a fairly new tank, no corals but am planning to set up a new tank in about two months. Should the power heads be used to generate surface flow or to create current throughout the tank to avoid "dead spots"?

Thanks

 

[Shaummy]

IMHO.... it's for both. You want good flow in both places, so setting up the right size/position/number of powerheads is key.

That number of powerheads is also dependent on the way your rockwork is set in the tank, and eventually the needs of your corals. Some like low flow..some require high flow.

 

[BrianKC]

IMHO.... it's for both. You want good flow in both places, so setting up the right size/position/number of powerheads is key.



That number of powerheads is also dependent on the way your rockwork is set in the tank, and eventually the needs of your corals. Some like low flow..some require high flow.

Yes, it's both surface exchange and keeping things suspended in the water column. My favorite layout is:
1. 2 bigger power heads at opposite ends of the tank pointed across the tank. Mount one high and one low. This will get a good horizontal vortex going that sends rippling water across the top for oxygen exchange from the high head and bottom-to-top exchange from the lower. Imagine a big conveyor belt moving the water across the top, down, back across the bottom, then back up.
2. A couple smaller power heads aimed orthogonal to the conveyor flow. This will create nice turbulence in the water column to keep things stirred up. Position these as needed to accommodate the flow needs for different specimens.

 

[deus ex machina]

If you have a skimmer and sump, surface agitation for oxygen exchange isn't as important. I set mine up one on top of the other on the tank wall to creat a gyre. Not much surface agitation. Seems to work pretty well.

 

[GregJames]

I put two identical heads on the same side at different heights. Then a wave maker aimed perpendicular to the other two power heads.

The two heads create a good circular motion and the wave maker mixes things up

 

[squid row]

Thank you. Is it bad to change the position around once per week or so? I have two and reposition them each water change