Fluval 304 question

[Deliverme314]

First, Hi all. New to this board.

Second. I just finished my initial setup of my new 90 gallon and when installing my fluval 304 filter it said when turning on to make sure that output is above the water level. Does anyone have one of these and keep it under the surface? This thing makes a ton of noise and agitates the surface which will difuse my Co2. I really want it under the surface but am worried it will screw something up.

Thanks.

[zzyzx]

I kept the outputs for a couple of 404s under the water with no problems. I now have Pro BioWheel 60s hook to the output of the Fluvals. The Fluval 404 or 304 output provide plenty of flow to turn the 2 biowheels on a Pro 60.

[anonapersona]

Do they mean just during start up? I could see where it might be more difficult to expell any air inside the filter if the output was below the water line. My 303 output is just below the water line.

[tnlguinn]

i have 2 404s 1 w/ biowheel and 1 regular output 3" inder the surface of the water to eliminate the whirlpool that is caused by the flow from the output hose. you can put it at the bottom of the tank if you want, it won't hurt it.

[Toro Driver]

I agree with the others, mine is about three inches below the surface. I set mine up two weeks ago so I can go with a CO2 setup as well. I think they want you to make sure its above the surface when you first prime it and start it up. Then your drawing water from only the intake and not the outflow.