Powerheads and direction?

[tomato clown]

I bought 2 new powerheads for 2 of my tanks, and I was wondering if they are supposed to be pointed in only 1 direction or if I should try to mimic a tidal effect by changing thier direction 2-3 times a day?
I would have to manually move them, but if needed it's ok with me.
Dan

 

[mal]

I have stationary phs' too. I change the direction a little when I clean. Just to change up the tank currents. It seems to help stir things up so I don't get build ups of waste so much. Also so my corals don't get used to growing one way like a plant to light. I have no idea if this would happen or not, but it's my theory.
[ December 08, 2001: Message edited by: mal ]