Spraybars, surface aggitation and overflows

2quills

2quills

Well-Known Member
When I think of tapering the holes I imagine smaller holes gradually increasing to larger ones as you get closer to the pump. I think the spray bars for the canisters are a good example as well. The holes are all the same size and I get more flow/force/volume of water flowing out of the holes closest to the end of the spray bar. I assume it's because water is traveling the path of least resistance. It has no where to go once it reaches the end of the line and the resistance it meets gets directed outward of the closest available path of least resistance. So in theory if you could find the right formula for making the holes gradually rise from smaller to larger and at what distance then ultimately you could find the right balance of force and flow being pushed out of them.
Personally I would probably try to design it in a way that supports the efficiency of your overflow. In my case for instance if I have two overflows (one on each side of the tank). Then I'd want more force and flow in the center of my tank. I would think it would help push particles and debri more efficiently to the overflows. If my overflow was in the center of my tank then I'd want to increase the flow equally on the sides/ends of the tank where the ripples would push stuff towards the center...etc.
 
al&burke

al&burke

Active Member
Good point Corey - on some air manifolds they actually reduce the sice of the header as you get to the end of it. The possibilties are endless.
 
posiden

posiden

Active Member
Quote:
Originally Posted by Al&Burke http:///forum/thread/382045/spraybars-surface-aggitation-and-overflows/20#post_3332968
No problem Posiden, good conversation, I still want to get the spread sheet out, I want the user to be able to input everything they have on the pump supply, pipe sizes, no of elbows, etc to calculate the head loss or pressure loss as I call it, it might help some people out with pump selection. Been really busy - but i will get it done, there are a bunch of inputs that I am trying to make user friendly for the non-engineering types, I don't mean this as an insult to anyone. There are a bunch or very intelligent people on this forum.
This is exactly how I think it should be. Even for the brain type folk. We all have the moments where we just want an answer.LOL.
 
J

jstdv8

Guest
ok, So if I have a 1" return pipe to get better pressure out of the holes on the spraybar I should reduce my pipe on the bar to 3/4" is that right?
And then I was thinking instead of doing a ring around the entire perimeter I would do something that looks like a tuning fork for lack of a better anaolgy. My return comes into the tank on the side (left back corner) so if I neck down right there to 3/4" and then split it so that the pipe runs the entire length of the back wall (4') and then caps at the corner. And then the other side of the "T" goes 26" along the side wall to the front of the tank and then accross the front of the tank the same 4' with no holes in the 26" side.
I'm thinking 10 holes on the front 4' and 10 holes on the rear.
it will be schedule 40 3/4" pipe and I don't really have the capabilities to taper the holes themselves, but I could have smaller (or larger) diameter holes on one end working up or down to a particular size at the other end.
Does that sound right?
I have a drill press at my dads I can use to get the holes nice and even.
Then to get the surface aggitiation I just leave all the parts unglued and just spin the pipe in the elbows until its hitting where I want?
Keeping in mind I'm not at all concerned with any water movement within the tank. The only purpose of this for my application is surface aggitiation without the use of any flow from my koralias. (And a fun DIY project :)
 
al&burke

al&burke

Active Member
What size is your line from your pump, I think your header (spray bar) should be one size larger. I think you should make 2 tuning fork designs with supplies on each one.
 
J

jstdv8

Guest
The supply line is 1" coming up the side of the tank, so inside the tank i need 1 1/4"?
If by two supply lines you mean two pumps thats not really cost effective, in which case I would jsut spend the extra money and get a couple more powerheads and only pay a small electrical bill per each (5w or so each) and put those down lower in the tank, like a couple of #2's
Right now I have a Quietone 4000 and its too big for my overflow, i have to really neck it down to keep it from putting too much water in the tank. So I was thinking If I need more flow I could add another overflow (or sell the two i have and buy a really big one) giving me about 1200 GPH going into the sump and then I gould open the Return pump wide open and supply power to the spraybar.
 
2quills

2quills

Well-Known Member
Those would be some pretty huge spray bars. With all due respect to the other guys...if this were me I don't see why you couldn't split the return from 1" down to two 3/4" or even two 1/2" lines. You already said that your pump is a little too strong anyways. IMO you should be able to split the line at the top of your tank and reduce it to two 1/2" lines (which technically isn't really reducing). The reduction would create more back pressure and would force the water out of the holes at a greater velocity. You could essentially slow the flow of your pump with the spray bars instead of with a valve. I do see what Al is saying about using larger spray bars but I personaly wouldn't want to have to see that large of pipe running around the top of my tank. At least not on a 120G. Again, I say that pvc is cheap. I would take the design that you want to use and try it with the different sizes. Start with less holes and work your way up untill your happy with it. JMO.
 
al&burke

al&burke

Active Member
I agree Corey, if you split the supply to two smaller lines then you won't have as large of a pressure drop, head loss. I am going to play around with it, have a look at my "New Sump" thread I posted the spray bars, they look a little big but we'll see how they work. Once I get my new pump this week I might play around with it a bit.
 
posiden

posiden

Active Member
Quote:
Originally Posted by 2Quills http:///forum/thread/382045/spraybars-surface-aggitation-and-overflows/40#post_3333112
Those would be some pretty huge spray bars. With all due respect to the other guys...if this were me I don't see why you couldn't split the return from 1" down to two 3/4" or even two 1/2" lines. You already said that your pump is a little too strong anyways. IMO you should be able to split the line at the top of your tank and reduce it to two 1/2" lines (which technically isn't really reducing). The reduction would create more back pressure and would force the water out of the holes at a greater velocity. You could essentially slow the flow of your pump with the spray bars instead of with a valve. I do see what Al is saying about using larger spray bars but I personaly wouldn't want to have to see that large of pipe running around the top of my tank. At least not on a 120G. Again, I say that pvc is cheap. I would take the design that you want to use and try it with the different sizes. Start with less holes and work your way up untill your happy with it. JMO.
Sorry, I disagree. Using two 1/2" pipes isn't the same as one 1" pipe. Circles and cylinders are funny things. The two 1/2" pipes would only be able to hold half as much as the 1" pipe. When ever you double the diameter of a cylinder you increase its volume by 4 times.
Also if you just go on the SA, the two 1/2" pipes only make up about half of the 1" pipe.
Could the user get away with it? In this case, maybe. Due to the fact that the pump is being choked down. The pipe would do the choking for him and not the ball valve, as you already stated. IMO, if the user was to use the 1/2" pipe. Using .125 diameter holes. He would need 16 of them. A smaller hole would require more of them.
 
al&burke

al&burke

Active Member
You would have to adjust the size of the holes to compensate for the reduction in flow, going smaller would increase the pressure loss, I can do a quick calculation after a change some water in my tanks.
 
2quills

2quills

Well-Known Member
Quote:
Originally Posted by Posiden
http:///forum/thread/382045/spraybars-surface-aggitation-and-overflows/40#post_3333206
Quote:Sorry, I disagree. Using two 1/2" pipes isn't the same as one 1" pipe. Circles and cylinders are funny things. The two 1/2" pipes would only be able to hold half as much as the 1" pipe. When ever you double the diameter of a cylinder you increase its volume by 4 times.
Also if you just go on the SA, the two 1/2" pipes only make up about half of the 1" pipe.
Could the user get away with it? In this case, maybe. Due to the fact that the pump is being choked down. The pipe would do the choking for him and not the ball valve, as you already stated. IMO, if the user was to use the 1/2" pipe. Using .125 diameter holes. He would need 16 of them. A smaller hole would require more of them.
Ok, looking at the pipe I could see how you could quadrupal the the volume of the pipe when you double the size. So two 1/2" might be cutting it a bit much. Perhaps spliting it with two 3/4" and keeping the valve for fine tuning would be a better option. Again, in this instance choking off some of the flow is kind of my point. But I guess it depends on how vigorous the user wants the ripple action to be.
 
al&burke

al&burke

Active Member
There has to be a sweet spot, velocity exiting each hole, total volume of water feeding the spray bar, angle in water, total number of holes and diameter. This is a classic fluid dynamics course in saltwater fish keeping. I thought I had my fluids book at home but I don't so that calulation is going to have to wait.
There is basically three components
Flow
No of Holes
angle in water
 
2quills

2quills

Well-Known Member
Yeah there is a sweet spot in there somewhere. Where it's at I have no idea. I just don't think I could live with seeing two 1-1/4" lines wrapping around the rim of my display tank. I'm an asthetics freak.
Depth of which the returns may be set under water could play a roll as well but I don't think that would be relevant in this case.
 
al&burke

al&burke

Active Member
I guess if you could tuck it up in the canopy and just have the holes in the tank, it might not look bad, as long as you had trim to hide it. Better yet make one out of acrylic to just sit inside the tank.
 
2quills

2quills

Well-Known Member
Yeah and they do make the clear pvc too but it's pricey. I like using the loc-line stuff. I've taken my spray bars off of my 55G and have gone with loc-line returns for both of the canisters that I'm running on there. I actually have them aimed upward towards the surface for all of my surface aggitation. I just have the basic 1/2" nozzles on each one and I have tons of ripples in the water. Maybe even too much some times. I have 2 750gph koralias and 2 150gph powerheads for flow in the rest of the tank. So far the set up seems to work pretty well.
 
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