# Positioning Spray Bars



## Dolly Sprint 16v (22 Feb 2009)

Gang@ukaps

Has anybody any thoughts on the best position to place spray bars.

On the back of the tank spray towards the front of the tank or on one of the sides which would spray to the other side.

Which of the two is considered the best for water distribution / filtering and flow with out breaking the surface of the water.

in addition to the above the spray bar has a series of holes are these hole better positioned to spray the water sub surface or 10 degrees (water level being zero degrees) or should you point the holes down @ 45 degrees.

Regards
Paul


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## Themuleous (23 Feb 2009)

It really depends on the tank and the hardscape.  Basically you want to position them in whichever way maximises the flow around the tank.  You may have to try several different alignments and see which works best for your tank 

Sam


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## TLH (23 Feb 2009)

If it's a long tank it's probably better on the end I would have thought, a short tank probably better on the back.


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## ceg4048 (24 Feb 2009)

Hi,
    In my experience spraybars almost always work better mounted on the back wall pointing across the short dimension of the tank, with the top of the bar very near the water's surface and with the holes all pointed exactly horizontal or no more than a couple of degrees down from the horizontal. If the footprint of the tank approximates a square then the distances involved are equal front-to-back versus left-to-right so the mounting wall may not matter much, however, most aquascapes using carpet plants along the front which makes the aft wall the best location for mounting from a flow pattern perspective.

As Sam points out though each tank is unique but the configuration described should be the starting point.

Cheers,


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## chris1004 (9 Mar 2009)

I totally understand your logic there Clive when it comes to your low level plants but was wondering how this arrangement affects the viewing of your fish if at all. 

My fish tend to spend a great deal of time facing into the current and as my spraybars are mounted at each end of the tank one horizontally level with the water surface (about 3-4" deep) and one almost vertically down wards (at the same level) this arrangement creates a circular motion accross the long side of the tank and the fishes flanks are exposed when they rest facing into the current either at the top of the tank or at the bottom albeit in opposite directions. Obviously they don't spend all of there time facing the flow but it is the vast majority esecially when not feeding. 

I would however have trouble mounting my spraybars on the rear wall of my tank due to the immitation rockface background that I have used which was the main reason for mounting them the way that I have in the first instance.


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## ceg4048 (9 Mar 2009)

Hi Chris,
           I guess the viewing issue depends on the type of fish, but I have no issues as I mostly keep tetras, who dart about the tank at whatever angle suits them, and dwarf chiclids, who hide along the crevices near the substrate. I suppose fish with high surface area finnage such as angels or discus might be affected more by the current and would tend to tun into it as you've observed. In any case if you have obstructions along the back then you're physically limited anyway so it's a moot point. 

Some observations of the the hydrodynamics and placement of the spraybars are addressed in Difference in drop checker readings in different positions

Cheers,


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## chris1004 (9 Mar 2009)

Not trying to get one over or anything like that Clive, (I really don't think I could anyhow even if I tried) I'm more interested in fish behaviour with relation to flow thats all. I would be very interested in input from anyone with regard to fish behaviour verses spraybar positioning / flow direction. 

I understand that your tank dimentions are 6x2x2ft so the distances that the flow has to cover must play a huge part in your decisions, unlike smaller tanks that are more commonly used. For the record mine is 48"x18"x21", I think that you would have huge problems if you tried to force the flow along the long side of your tank though so maybe we are both limited by what we have?.

Whilst on the subject of spraybars I have been wondering about my other pipework positioning specifically the outflows to the filters. If you had two of these would you put them in the obvious positions of one at each back corner near the bottom or would you put them at different levels? I've even been considering the posibility of installing some piping under the gravel and hiding a filter outlet in the middle of the tank when I next replenish the substrate or set up another tank. The obvious drawback to this could be keeping the pipes clean but I reckon this could be overcome with some serious thought.


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## ceg4048 (11 Mar 2009)

Yeah, hiding them near the bottom is a good idea. I guess it depends on how finicky you are about the visual impact. I just place them in the normal locations in each of the two rear corners and as the tank fills in they get hidden, but yes, a more open scape is less forgiving. These don't seem to have as dramatic effect on the flow patterns that much as the effluent pipes but probably have a greater effect on the amounts of detritus/debris that get picked up. That would be more trial and error, tough to predict.

You're right in that the tank size has a major impact on the decision making. Large tanks have a very difficult time with dead spots and low flow areas simply due to friction and space but the same principles apply to smaller tanks especially if the pump capacity is scaled down. It's just a matter of degree really.

I'll let someone else comment on behavioral issues as a function of effluent position.  

Cheers,


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