# Spray bar length????



## Rob in (ca) (Aug 24, 2012)

this was from a few weeks ago 

http://www.plantedtank.net/forums/showthread.php?t=191599


----------



## Diana (Jan 14, 2010)

That tank is so long that the one-end-to-the-other idea does not work unless you have a lot of gph. 

I have my spray bar in 2 parts. The main supply comes in over the middle back, then it Tees with each half of the spray part starting several inches from the Tee. The holes are aimed at the front of the tank. The parts with holes are about 18" long, each, so roughly 50% of the back wall has spray bar holes.


----------



## HypnoticAquatic (Feb 17, 2010)

most people put them on the back and in doing so allows for more holes = less current, some say they need more maintenance but they really shouldn't, if there clogging up it should have wider holes, in doing so it also allows for a higher turn over rate while keeping the current down so your fish still are happy and not stressed by being in a vortex.

with that said there is no "right" way there are just ways to get the most out of what you want vs others ie a 12" spray bar with the same size holes vs a 24" spray bar same holes etc will have much much less current while keeping the same flow rate, so it might work for your tank but might not work for others.

another thing is people saying that if your water drops to low you can spray out all your water, well why not just make larger holes keeping the same flow without the stream effect then you can up the turnover rate if you wish.


----------



## Hoppy (Dec 24, 2005)

A spray bar has a fixed flow rate coming into it, so there is no way to increase the flow rate beyond that. Ideally you want each hole in the spray bar to have the same amount of flow coming out of it. If the holes are too large, water doesn't come out of the holes farthest from the inlet, at all. If the holes are too small, it restricts the flow, reducing the flow rate. The best way to design the spray bar is to:
1. Keep the inside diameter of the spray bar larger than the inside diameter of the hose feeding it. This slows the flow velocity in the spray bar.
2. Make the total area of all of the holes a bit less than the area of the inside of the hose feeding it. This gives you minimum flow rate loss, while still getting flow from all of the holes. So, the number of holes times their diameter squared should be slightly less than the inside diameter of the hose squared.
3. Avoid really small holes, like 1/16" or less, because they will soon be partially clogged with biofilm.


----------



## OrangeSoda (Jan 15, 2011)

Spray bars are usually mounted lengthwise along the back to create a constant circular flow. Along the top, down the front, rearward along the bottom, and up the back (same as an average HOB BTW). Clockwise if you look at your tank from the left end.


----------



## HypnoticAquatic (Feb 17, 2010)

one thing that u can do for a long spray bar with larger holes is to make another bar on top and have it T into the bottom spray bar this will allow the flow to even out if you do choose to go that way, you could also use a smaller pipe behind it so its not visable an do the same thing but it all depends what your looking to get out of it.


----------



## ChadRamsey (Nov 3, 2011)

thx for all the input folks.





HypnoticAquatic said:


> most people put them on the back and in doing so allows for more holes = less current, some say they need more maintenance but they really shouldn't, if there clogging up it should have wider holes, in doing so it also allows for a higher turn over rate while keeping the current down so your fish still are happy and not stressed by being in a vortex.
> 
> with that said there is no "right" way there are just ways to get the most out of what you want vs others ie a 12" spray bar with the same size holes vs a 24" spray bar same holes etc will have much much less current while keeping the same flow rate, so it might work for your tank but might not work for others.
> 
> another thing is people saying that if your water drops to low you can spray out all your water, well why not just make larger holes keeping the same flow without the stream effect then you can up the turnover rate if you wish.



i cant really make one that is 6 ft long that runs the length the back wall, i would imagine that water would fail to come out the last foot or so.

So i guess that i will make one that is about 4 ft and center it along the back wall.




Hoppy said:


> A spray bar has a fixed flow rate coming into it, so there is no way to increase the flow rate beyond that. Ideally you want each hole in the spray bar to have the same amount of flow coming out of it. If the holes are too large, water doesn't come out of the holes farthest from the inlet, at all. If the holes are too small, it restricts the flow, reducing the flow rate. The best way to design the spray bar is to:
> 1. Keep the inside diameter of the spray bar larger than the inside diameter of the hose feeding it. This slows the flow velocity in the spray bar.
> 2. Make the total area of all of the holes a bit less than the area of the inside of the hose feeding it. This gives you minimum flow rate loss, while still getting flow from all of the holes. So, the number of holes times their diameter squared should be slightly less than the inside diameter of the hose squared.
> 3. Avoid really small holes, like 1/16" or less, because they will soon be partially clogged with biofilm.


GREAT info! I believe that i read that in the past in one of your old posts.

I will follow it to a "T"

Thx


----------



## BoxxerBoyDrew (Oct 16, 2005)

In my 55g I have 2 Fluval 205s, and I had 2 spray bars at the right end of the tank. They were the width of the tank, so right at 11.5" of spray bar length after the 90* elbow. I then placed the 2 inlets on the left end of the tank like You were talking about in version 1. It worked VERY WELL, and I could see the waste particles flowing in the long circular pattern like you were talking about.

The only thing I could tell was a problem was at the left end at the bottom of the tank I was getting some BBA algae growing on the substrate. The substrate was 6+ year old Flourite, and I THINK it was a lower Co2 concentration that might have caused the BBA. BUT at the same time I started getting BBA on the spray bar that the Co2 was coming out of, so that kind of shoots holes in the whole Co2 thing! LOL Of course it had been a month since I had done a water change, because I knew I was going to change the substrate out and go with MGOPS and Black Diamond blasting grit for the new substrate, so I let the water changes go! I know I was being lazy!

So now that I have changed the substrate out I am thinking of putting 1 spray bar along the right side a few inches under the water, then putting another spray bar along the left end a few inches above the substrate to see what kind of flow pattern I will be getting. Also to see if I get better Co2 coverage. I will leave the intakes of the 205s on the left end and raise them a little so they are pulling the water from the midpoint of the tank. 

I am also thinking of putting reactors on both outputs too! I have a few extra Filter bodys to build cerges type reactors from a old R/O unit, but I am unsure if I can get away with just putting a "T" in the single output from my Co2 bottle, or I will have to run a second bubble counter/ needle valve setup to keep the same amount of Co2 going to each reactor? 

So I will be doing this in the next few days, and I will let Ya know how it works out! 

With the FX5 you are running you should have plenty of flow to put what ever kind of spray bars you want to! I have learned to drill the spray bar holes a bit smaller that you were planning to, then see if the flow is how you want it, and if not step up to the next size drill bit. It is easier to make the holes bigger compared to building a new spray bar if the holes are to big!

I also use a 1 gallon bucket to check the output of the filter after making the spray bar as well! Just time how long it takes to fill up the 1 gallon bucket when the spray bar is where you are going to mount it in the tank, then you can figure out how many GPH your filter is actually running at the head hight and if the output from the spray bar holes is correct.

Hope this helps, and I will let Ya know how my experiment works out too!

Have FUN!!!
Drew


----------



## ChadRamsey (Nov 3, 2011)

Thx Drew. Great information. 

Because of the length of my tank, i am leaning toward the spray bar that is about 4ish ft long and mounted on the back wall. Like you experienced with the end to end set up, it will probably give me better CO2 delivery throughout the tank.

My new question is: 

Do i feed the spray bar from one end OR through a T-fitting in the middle of it? 

My fear about the T-fitting idea is, once the FX5 puches the return water up to the spray bar and it slams into the T, will it reduce the flow? 

BUT the advantage to the T-fitting is that it will evenly distribute the CO2 infused water evenly across the spray bar and therefore throughout the tank.

Keep me posted Drew on what you do with your set up.


----------



## Steveboos (Apr 7, 2012)

I ran a DIY Spraybar on my 125 with a Fluval FX5 for months with African cichlids. You want to make it as easily hidden as possible and you want the flow to remain constant. If it has too much flow, you can always drill more holes or large diameter holes.

Here's the video of my Spray bar i was running for a long time I still have it and need to sell it or something haha.

http://youtu.be/1J1t3h3mWbY


----------



## Hoppy (Dec 24, 2005)

ChadRamsey said:


> Thx Drew. Great information.
> 
> Because of the length of my tank, i am leaning toward the spray bar that is about 4ish ft long and mounted on the back wall. Like you experienced with the end to end set up, it will probably give me better CO2 delivery throughout the tank.
> 
> ...


A spray bar will work best if it can act like a manifold - a volume where the flow velocity is very slow. That makes it a plenum, a volume containing water under pressure, but with little flow velocity, so no pressure difference between one end and the other. The pressure drop is roughly proportional to the velocity squared. With that, it makes no difference where the flow enters. You do that by using a relatively large diameter for the spray bar compared to the diameter of the hose bringing water in. The flow velocity will be roughly proportional to the square of the ratio of the inlet hose and the spray bar - if the diameter of the spray bar is double that of the inlet hose it slows the flow velocity to 1/4 of the velocity in the inlet hose, and the pressure drop to 1/16th of that in the hose. This makes the spray bar harder to hide, so something less than 2-1 ratio can be used.


----------



## Diana (Jan 14, 2010)

Mine is fed through 1/2" PVC,centered, has a Tee, and the 2 parts of the spray bar are also 1/2" PVC.


----------



## ChadRamsey (Nov 3, 2011)

Steveboos said:


> I ran a DIY Spraybar on my 125 with a Fluval FX5 for months with African cichlids. You want to make it as easily hidden as possible and you want the flow to remain constant. If it has too much flow, you can always drill more holes or large diameter holes.
> 
> Here's the video of my Spray bar i was running for a long time I still have it and need to sell it or something haha.
> 
> http://youtu.be/1J1t3h3mWbY


i saw your video during my google search prior to this thread. Thx for the input. Yeah. Hidding it will be an issue i guess.





Hoppy said:


> A spray bar will work best if it can act like a manifold - a volume where the flow velocity is very slow. That makes it a plenum, a volume containing water under pressure, but with little flow velocity, so no pressure difference between one end and the other. The pressure drop is roughly proportional to the velocity squared. With that, it makes no difference where the flow enters. You do that by using a relatively large diameter for the spray bar compared to the diameter of the hose bringing water in. The flow velocity will be roughly proportional to the square of the ratio of the inlet hose and the spray bar - if the diameter of the spray bar is double that of the inlet hose it slows the flow velocity to 1/4 of the velocity in the inlet hose, and the pressure drop to 1/16th of that in the hose. This makes the spray bar harder to hide, so something less than 2-1 ratio can be used.


Was that in English?

Ok. Let me whip out my crayons and see if i can draw a picture of what you just said that i can understand...

WOW, so by what your saying... (the FX5 hose is 1 inch)... my spray bar should be 2" in diameter? THATS HUGE!! But if i dont go that big, then my flow velocity will be significantly higher. Causing turbulent water that shrimp couldnt live in. Right?





Diana said:


> Mine is fed through 1/2" PVC,centered, has a Tee, and the 2 parts of the spray bar are also 1/2" PVC.


What is the size of your hose? tank? pictures would be awesome. thx


----------



## Steveboos (Apr 7, 2012)

I did 3/4" PVC and 1" ID vinyl hose. That gave me TONS of pressure with 5/32" holes drilled every 2 inches. So i would increase the diameter of the holes and make them closer together to slow the flow. But 3/4" PVC is the best option I've found for a FX5.

Oh and nice to know my videos comes up first in a google search, glad it's being used!


----------



## Hoppy (Dec 24, 2005)

ChadRamsey said:


> i
> WOW, so by what your saying... (the FX5 hose is 1 inch)... my spray bar should be 2" in diameter? THATS HUGE!! But if i dont go that big, then my flow velocity will be significantly higher. Causing turbulent water that shrimp couldnt live in. Right?


Isn't that FX5 hose only 1 inch in outside diameter? If so, the inside diameter will be considerably less, as little as 5/8 inch. It is the inside diameters that are significant, not the outside. If you don't go that big, it has no effect on the fish, but it makes it harder to get uniform flow along the length of the spray bar - high flow near where the water enters, low flow far from where the water enters. The flow velocity out the holes depends on how much combined area the holes have versus the inside area of the hose feeding the spray bar. The smaller the holes, the faster the flow.


----------



## HypnoticAquatic (Feb 17, 2010)

like i said earlier you can use a bypass to help keep the pressure more constante through out the whole line 

╔════╬════╗
╚════╩════╝

kinda like that the more connections help allow the pressure to balance out instead of having high to low flow for a system like this

╚══════════

doing it that was can help u keep the diamater down while keeping the flow the same, and u can do it on top/behind/below the spray bar, i would to it on top or behind.

but like hoppy said the larger diameter for a single line is the way to go! if u do it that way.


----------



## ChadRamsey (Nov 3, 2011)

Hoppy said:


> Isn't that FX5 hose only 1 inch in outside diameter? If so, the inside diameter will be considerably less, as little as 5/8 inch. It is the inside diameters that are significant, not the outside. If you don't go that big, it has no effect on the fish, but it makes it harder to get uniform flow along the length of the spray bar - high flow near where the water enters, low flow far from where the water enters. The flow velocity out the holes depends on how much combined area the holes have versus the inside area of the hose feeding the spray bar. The smaller the holes, the faster the flow.


the ID of the hose i use for for the FX5 id 1"

i found black PVC and my options are 1.5" or 2"

2 inch is just so HUGE!


----------



## Hoppy (Dec 24, 2005)

You can use 1" white schedule 40 PVC painted black with Krylon Fusion. That size pipe is about 1.049" inside diameter, so its inside area is 10% bigger than the inlet hose.


----------

