Spray Bar or Not?

[RossW]

Do most people tend to use spray bars or the single output thingy?

Also, do you tend to put it out of the water to max. splash or just under the surface to reduce noise a little?

[dan2x38]

One issue with HOB filters is that the water is picked up right under the filter with the output right over the pick-up. Of course there is circulation but it tends to re-filter water already filtered as you can see. You can use a PH to create some water movement it helps to prevent dead spots in your tank. Using a spray water prevents that tendency by disturbing the filtered water away from the pick-up. You want to keep the bar of above the water surface to help increase adding O2. It also breaks the water surface to help with gas exchange. There is a film that builds up a little on the water surface so that too is broken up so it does not decrease gas exchange. Any surface gunk oils, protein, hair, etc. gets moved around as well for it to get filtered hopefully.

[beowulf]

I think he is talking about canister filters.  I use spray bars personally but it depends on how much flow and how concentrated you want the flow.

[babblefish1960]

I have used spray bars personally on all of my canister filters for many years now, and all of them are below the surface, as all of my tanks are planted; splashing water on the surface, besides being irritatingly noisy, is counterproductive to the gases we try to keep in the water column for the plants. Additionally, the plants benefit from the flow throughout the tank around them.

[dan2x38]

Yes agreed if you are injecting CO2 would not want to increase gas exchange. Of course not putting the spray bar to far above the surface to create Niagara Falls... 

[kennyman]

I run a spraybar on my 55 as it allows for a more diffuse flow pattern. The jet makes it look like you are moving more water, but you ar not. You are just concentrating that same flow into a stream.