# DIY Spraybar question



## Airphotog (Aug 21, 2009)

If you can feed from both ends you would get good results. Feeding from the middle would be better than from one end.


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## jmhart (Mar 14, 2008)

Airphotog said:


> If you can feed from both ends you would get good results. Feeding from the middle would be better than from one end.



Feeding from both ends with the same pump would be less efficient than feeding from the middle. There would be more resistance. 


Feeding from the middle will work.


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## deeda (Jun 28, 2005)

I'm not using a needle wheel pump but I feed a 6' DIY spraybar with my Eheim 2262 filter from the end only. Works great.


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## BayBoy1205 (Jan 25, 2006)

deeda said:


> I'm not using a needle wheel pump but I feed a 6' DIY spraybar with my Eheim 2262 filter from the end only. Works great.


What size of pipe did you use, how many holes, what size of hole, and the spacing?

Thanks,
Matt


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## ron521 (May 12, 2008)

Mine wasn't DIY, but I used a T fitting with two Eheim spraybars for a long time with good results.


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## jerrytheplater (Apr 11, 2007)

BayBoy1205 said:


> What size of pipe did you use, how many holes, what size of hole, and the spacing?
> 
> Thanks,
> Matt


To calculate the number of holes in a spray bar to minimize back pressure and maximize flow do the following calculations:

1 Calculate area of outlet on pump. (Pi)(Inside Dia of pump outlet)^2 / 4

2 Decide on hole size. I used 1/8" Dia. on mine for a Mag 7 pump.

3 Calculate area of one hole using above formula

4 Divide step 1 answer by step 3 answer.

5 Round down the answer to the next lowest whole number. This is the number of holes you need. The size of the pipe does not matter as long as it is larger or the same as the pump outlet.

6 Space out the holes over the length of your spray bar. If you want them evenly spaced, just do the math and space them out.

7 I find if you countersink the hole in the spray bar you will get a spray out of the hole rather than a stream. This may or may not interest you. I don't countersink to stick with a stream.


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## deeda (Jun 28, 2005)

BayBoy1205 said:


> What size of pipe did you use, how many holes, what size of hole, and the spacing?
> 
> Thanks,
> Matt


I used 1/2" CPVC, 70" long x 33 holes, spaced evenly apart. All the holes were originally 1/8" diameter but we enlarged the holes to 3/16" diameter on the last two feet of the run to balance the velocity of the water evenly along the entire spraybar.

BTW, we did use the formula that jerrytheplater referenced above.


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## Firestarter (Dec 28, 2009)

Ok I am terrible at math what does this formula mean?



jerrytheplater said:


> 1 Calculate area of outlet on pump. (Pi)(Inside Dia of pump outlet)^2 / 4


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## Nymsley (Mar 24, 2009)

Firestarter said:


> Ok I am terrible at math what does this formula mean?


It calculates the area of a circle, the pump output in this case.
If you simplify it, it'll look more familiar to you. Sorry, if I didn't explain it well enough.

A = area
d = diameter = 2*radius = 2r
Pi = π ≈ 3.14

A = π * d² / 4
A = π * (2r)² / 4
A = π * 4r² / 4
A = π * r² = πr²


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## BayBoy1205 (Jan 25, 2006)

Thank you so much. Hopefully I will get to assemble the spraybar this weekend.


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## Guns286 (Sep 17, 2009)

Nymsley said:


> It calculates the area of a circle, the pump output in this case.
> If you simplify it, it'll look more familiar to you. Sorry, if I didn't explain it well enough.
> 
> A = area
> ...


Am I the only idiot that does'nt even understand the simplified version!? I think the only way to solve this problem is to either do the calculations for me or, pretend you're explaining it to a 12 y/o :icon_roll
My spray bar is 20" long, 3/4" pvc. It will be attached to a Fluval 405 (not sure of the GPH) and placed in the tank VERTICALLY.


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## Nymsley (Mar 24, 2009)

The number that jerry asks for is the inner diameter of the output tube. Not sure about PVC, is that 3/4" outer or inner diameter?
From there you can either decide how many holes you want or what diameter you want, then you can figure out the other number. I think that since its vertical, you're going to have more resistance at the bottom holes. Might go for slightly smaller holes or possibly less holes than the calculated number.


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## jgb77 (Dec 13, 2006)

Here is a link for inner and outer diameters of various pvc pipe sizes:
http://www.engineeringtoolbox.com/pvc-cpvc-pipes-dimensions-d_795.html
John


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## BayBoy1205 (Jan 25, 2006)

I finished my plumbing yesterday. The spraybar works great! The spraybar ended up being 2' in one direction and 1' in the other. Wasn't sure how feeding it with a T was going to work. 
I ended up using 1/8th inch holes spaced about 1.5"

The math worked great!

(3.14159265 * (5/8)^2 )/4 = X area of the pump outlet
(3.14159265 * (1/8)^2 )/4 = Y area of the drill bit used

Number of holes = X/Y

Thank you all for the help!


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## jart (Jan 17, 2003)

I'm curious as to how your spraybar is oriented. In other words, is it just above the substrate, or just below the surface of the water? or someplace in between?

Since you are using a needle wheel pump, I suppose it might make more sense to mount it just above the substrate.


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## daewoo59 (Aug 2, 2010)

*DIY spray for Eheim filter 2217*

Just see my picture,i had one more old spray bar extented with the original spray bar extented with the clips bought extra.Remove the end cap.U can see water spread over entire tank.For me it is this Eheim filter 2217 working well


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## theatermusic87 (Jun 22, 2014)

jerrytheplater said:


> To calculate the number of holes in a spray bar to minimize back pressure and maximize flow do the following calculations:
> 
> 1 Calculate area of outlet on pump. (Pi)(Inside Dia of pump outlet)^2 / 4
> 
> ...



Even though it's an old thread, I thought the original participants would get a kick out of my use of this formula...

I calculated needing 9 1/8" holes for my 200gph fountain pump, and I ended up having jets powerful enough to spray water across my 20 gallon tank and onto the floor...

I ended up drilling 23: 1/8" holes and 5: 3/16" to get the pressure down to a resonable amount


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## PlantedRich (Jul 21, 2010)

Fun thing about spray bars? For those who put them just below the water line and aimed across the tank, it can be bad if you leave home long enough for the water to drop below the spraybar. Without the water covering it, the water may shoot out over the tank side. 

The lady checking my tanks was sure there had to be a bad leak as there was water all over the floor and the tank was half dry!


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