Powerhead pointed at the surface or not?

[locnload]

Hello all,
Got a quick question. I just got a new powerhead. The instructions say to point the nozzel at the surface of the water. I've always had my flow pointed down at my LRs.
Do you know up at the surface or down?
Thanks

 

[pallan]

I think it depends on what you want for circulation and how the current flows in your tank. If you do not have enough movemment on the surface of your tank you will see a film buildup there and I read somewhere it will effect the gas exchange or something like that. I have one pointed at the surface and it creates a nice even flow in a circle around the tank.

 

[fisherson]

Same here in my 10 gallon i have it aimed slightly towards the surface to mix it up. I had the film for a while and it started almost suffocating everything once i got the powerhead in there everything was alot happier. But in my 55 because of all the pumps and skimmers and filters i don't bother aiming one at the surface