Canister output nozzle placement

[billylee]

I've had this below the water line for years so its more quiet
but some say it should be above the surface. Whats correct?

 

[haynchinook334]

is there just that one filter?

 

[haynchinook334]

if it is then, i'll place it above the water line (to break water tention)
if you are running a HOB filter aswell, then you can run the canister outlet below water line.

 

[BushFishRox]

I always put it below the surface to lower noise but point at the surface at roughly a 45* angle to agitate the surface which is why some say to put it above the surface...

 

[OnceLoyal]

I agree with Bush. Def. under the water line pointed up for surface aggitation.

 

[nfored]

I have mine 1 inch under the water hooked to a spray bar. This gives me wide agitation next to the retun, and also nice circulation. I have two retuns one on each side of the tank pointing at each other, one is on the bottom of the tank and one is 1 inch bellow the water line.

 

[Oreo]

For the last few years I've used a single canister w/ outlet below the water line pointed straight up. For the same reasons- to keep it quiet. It's worked fine generally but this year the heat & less AC usage has left my fish gasping at the surface. So I had to add an airstone. So my conclusion is that it works as long as everything else is in decent condition, but if you're heavily stocked or the water temp gets a little warm this method isn't as effective as more vigorous surface agitation.