# Fluval Canister Filter Spray bar



## yodapoolman (Mar 29, 2011)

So I'm thinking of ordering Fluval External Canister Filter Spray Bar Kit A-235 (a spray bar) to help with film on the top of the water but also have an easier flow for my plants. 

What's the best position and direction of this attachment? I just upgraded to a normal 55g (from my 55g tall) so I'm looking to make some changes.

Thanks!


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## Romad (Jun 28, 2009)

Definately pointing to the water surface for freshwater and plants.


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## yodapoolman (Mar 29, 2011)

So should I then position it length-wise just below the surface and have it pointing up?


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## Byron (Mar 7, 2009)

You may have to fiddle with it a bit. I find that when the holes are directed straight into the end glass (and the spraybar should be placed along the end wall of a tank, just below the surface, and at the end opposite to the filter intake if possible) you can get a slight flow across the surface but the main flow goes down the wall. You do not want the holes directly across the surface because this will be too much surface disturbance (for planted tanks) and inadequate movement down through the tank.

Fish species also have a bearing, and floating plants of course.

Byron.


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## Romad (Jun 28, 2009)

I have it pointed toward the water surface but not completely if that makes sense. Just enough to break the surface but my plants don't reach the top of the tank yet. What Byron said makes good sense.


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## marlin (Jul 23, 2011)

Byron, what effect does surface disturbance have on a planted tank?


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## yodapoolman (Mar 29, 2011)

If I'm not mistaken, it disrupts the gaseous exchange between O2 and CO2. Plants need the CO2 and give off the O2. So when the surface is agitated, more O2 is added, or maybe it's that the CO2 is "released" due to the agitation.

Just my basic understanding but I'm sure Byron will correct any false aspects and add a lot more professional insight


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## genewitch (Jun 27, 2011)

yeah - *surface* agitation evidently is not very helpful for the plants but i've always had luck with bubbles and plants, i put a stone near the roots of a plant and the plant grows like crazy for the weeks i leave it there.

You could get the contraption that takes air and puts CO2 in the water, although i have no idea how good those are at actually putting CO2 in the water.

Byron told me to shut off surface agitation at night (i think) and if i must have it, use it during the day. I'm thinking of putting the air pumps and lights on a timer circuit to achieve that end on my larger tank.


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## Byron (Mar 7, 2009)

As others have correctly pointed out, surface disturbance drives CO2 out of the water before plants can fully use it; it also brings more oxygen into the water, which can also be detrimental to plants. [I explain this more in my article "A Basic Approach to the Natural Planted Aquarium" at the head of the Aquarium Plants section.] Assimilation of CO2 from the water through the leaves of aquatic plants takes longer than it does in air, about 4 times longer, so driving the CO2 out is only removing valuable nutrients for the plants.

As for airstones, they should not be used night or day in planted tanks. If you add CO2 via diffusion during the day, an airstone at night can help to dissipate excess CO2, but that is another matter entirely.

Byron.


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## marlin (Jul 23, 2011)

I have a little movement at the surface from my hob filter, should I be concerned about the little movement it is creating? 

Here are videos of my surface water movement.


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## genewitch (Jun 27, 2011)

marlin said:


> I have a little movement at the surface from my hob filter, should I be concerned about the little movement it is creating?
> 
> Here are videos of my surface water movement.
> 
> ...


well, if you want less, fill the tank more. My 30g has that style of filter and about that much motion, and all the fish and plants are doing fine.


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## Byron (Mar 7, 2009)

marlin said:


> I have a little movement at the surface from my hob filter, should I be concerned about the little movement it is creating?
> 
> Here are videos of my surface water movement.
> 
> ...


I would not term that "little" but rather approaching the excessive. While the plants might manage (the CO2/oxygen exchange will be significant with this much surface disturbance) through this, I would be even more concerned over the fish. I don't know what species are in this tank, but if they are forest fish they should have a means of avoiding that much water movement. It is stressful if they have no escape day and night. On the other hand, some catfish such as certain pleco and spotted woodcats, hillstream loaches, etc. need this sort of flow or they will be stressed out and thus weakened.

This is my only complaint about HOB filters in general. They are absolutely exceptional in a tank with Hillstream Loaches, but are less than satisfactory with quiet water fish.

Byron.


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## Electric (Apr 8, 2011)

I cut down a replacement aquaclear filter sponge (fairly porous), and attached it to the output chute of my HOB filter. The sponge is partially submerged in the tank and really cuts down on surface agitation and water current. I'll see if I can attach pictures when I get home form work.


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## genewitch (Jun 27, 2011)

Electric said:


> I cut down a replacement aquaclear filter sponge (fairly porous), and attached it to the output chute of my HOB filter. The sponge is partially submerged in the tank and really cuts down on surface agitation and water current. I'll see if I can attach pictures when I get home form work.


I would say "brilliant" but i'd monitor ammonia and nitrite levels to be safe, you are technically impeding the flow. Byron has tanks that have no filtration, so he may be a bit biased against surface agitation :lol:


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## Electric (Apr 8, 2011)

The sponge is very coarse, with open cells averaging 1-2 mm in diameter. The water level in the filter does go up a very small amount, so flow is reduced, but not by much. If your filtration/ bioload is marginal, then it may be a concern.


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## marlin (Jul 23, 2011)

My filter is on the far left side of the tank so the fish do have from the center to the right side where there is no current although they do swim the whole tank.

I have Tetras and 1 SAE and all seem to be doing well.

As for plants, all have new growth and seem to be doing well too.


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