# Placement of filter outlet.



## drabbers (Mar 22, 2005)

I have a 36 x 15 x 15 inch tank and have recently purchased a Fluval 104 canister filter. I currently have the filter outlet in the back right corner but this has resulted in the plant all leaning with the flow and not straight up. How have you lot got around this ?


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## trenac (Jul 16, 2004)

Welcome to APC  

First make sure that the flow rate is turned down. You can also turn the outlet toward the back glass where the blunt of the flow is running along the glass away from the plants. If that does not work, then try moving the outlet to another location away from the taller plants if possible.


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## chubasco (Jan 16, 2005)

drabbers said:


> How have you lot got around this ?


Ah, another poster from the UK, or Commonwealth somewhere, welcome.
Does the outlet have a spraybar? If so, how long of one? Trena's suggestion
is a good one where the brunt of the spray is hitting the back glass. Using
a longer spraybar might help as well... :smile:

Bill


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## zeek (Jan 5, 2005)

Another option is to drill more holes in the spraybar, pointing in different directions.


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## Raul-7 (Feb 4, 2004)

Fluvals don't have spraybars. Other than Trena's recommendation, remember that once the bacteria colonies settle in the filter media the flow will drop significantly.


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## Overfloater (Apr 2, 2004)

I had a 204 on a similar sized tank and I opted to make a spaybar from PVC. The Fluval spout is designed to produce current and cause turbulance on the surface. The spraybar distributes the output over a greater area thereby reducing the current.


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## Jim (Apr 4, 2005)

*Water Circulation*

I'm a little unclear on the conventional wisdom regarding water currents in a planted tank. How much agitation and current should there be in a planted tank? What impact, if any, does current and circulation have to do with algae growth?

I'm using a Fluval 404 with my 85G planted tank and have the outlet just below the water surface for agitation. Is a spraybar type return preferred and if so, why?

Thanks,

Jim


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## shieber (Jan 23, 2004)

You only need enough water movement to keep getting nutrients to the surfaces fo the plants. For that you don't need to make you fish feel like they are swimming upstream all day. Otoh, most plants don't mind if the current is pretty strong. You won't mfind much scientific data on how much water flow an aquarum needs, whether planted or not. Bu tthe good news is that well planted aquaria are not very fussy about filtration.

I think anyone would be hard pressed to detect any diff in filtering effects with or without a conventional spray bar. Thos little hose tend to make strong localized currents, and being spread out, help to spread out the output. But the force of the flow from the end of an open pipe generally will do just as well. Those outlets with squished fan-shaped ends tend to increase the water velocity too.

Of course, with a long enough spray bar and enough little holes the effect on the water velocity at the spraybar holes will be the same as having one large hole.

If you want to reduce the strength of the current at the outlet, the large the opening, the lower the velocity. Mounting a Python gravel tube on the end of the output has this effect, although is too unsightly to be recommended ;-)

One way to increase the outlet opening size is to add outlets. You can do this with a spray bar and lots of holes. Or you can put a tee fitting inline on the output between the filter and the aquarium and run two (or more) lines from the tee(s) to the tank.

If you want to watch the long tall plants wave in the currents, you can use a SCWD for a tee fitting 

There is nothing inherently better about spray bars. They were originally designed, I believe, to provide for a lot of water-surface-air contact and surface agitation -- things desirable in fish only tanks but not in nicely planted aquaria.

Good luck,
sh

Good luck,
sh


Jim said:


> I'm a little unclear on the conventional wisdom regarding water currents in a planted tank. How much agitation and current should there be in a planted tank? What impact, if any, does current and circulation have to do with algae growth?
> 
> I'm using a Fluval 404 with my 85G planted tank and have the outlet just below the water surface for agitation. Is a spraybar type return preferred and if so, why?
> 
> ...


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## hoppycalif (Apr 7, 2005)

*Spray bars*

We don't want a strong surface current when we use CO2 injection. That agitation of the surface will just cause more of the CO2 to be lost to the air above the water. I made a pvc spray bar for my Fluval 104, using the type of pvc that isn't made for lawn sprinklers, etc. - it is smaller in diameter for a given size, is an ivory color instead of white. Unfortunately, it will be unsightly, but I am hoping the plants will soon grow to cover it up. I also extended the suction pipe so that it is at the opposite end of the tank from the spray bar, which is about 10% of the depth up from the bottom, but has so many holes that the current should be extremely slow. When I finally get the aquarium up and running I will report back if there is any problem with this set up.


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