Ideas to help increase flow

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  #1  
Old 08-06-18, 01:33 PM
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Ideas to help increase flow

I am building a waterfall/river in the backyard. It's about 80 feet long. The problem I'm having is with the water flow. I have a 1 HP Hayward Power Flo Matrix pump pushing water to the top of the river that spills out as a waterfall. That didn't push the water hard enough downstream so then I purchased a 3HP Pentair IntelliFlo pump and put it near the top of the river just to push more water downstream (See picture attached). However the river still isn't flowing as I'd like it to. Does anyone have any ideas on how I can improve water flow? I really wanted it to look like a fast moving river but haven't been able to achieve that! I will take any suggestions as I'm very frustrated at this point. THANKS!
 
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  #2  
Old 08-06-18, 02:45 PM
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You need a larger pump to increase the gallons per minute.

How much change in elevation is there at opposite ends of the "river"?
 

Last edited by Wirepuller38; 08-06-18 at 02:48 PM. Reason: Added text.
  #3  
Old 08-06-18, 02:59 PM
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Always put the pump at the bottom. Pumps can pump and push water very well but they are weak at sucking water uphill. So, pump goes at the bottom.

Use the largest diameter piping that you can and minimize the bends. Try to avoid 90 degree fittings at all costs. Think of the water like a race car. Sharp bends slow it down and burn off flow volume and pressure.

The pump you have chosen is a pool pump. It's designed for pushing water through a filtration system but doesn't have the best flow volume for the horsepower. For a river you want flow volume but don't need pressure. Best will be a pump that is NOT self priming and does not generate high pressure.
 
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Old 08-06-18, 03:02 PM
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Is there a certain pump you can recommend that would work better in my situation?
 
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Old 08-06-18, 04:02 PM
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The pump needed depends on lift (head) and diameter of pipe.
Two things we have no idea of.

Bigger pipe = more flow at lower pressure
 
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Old 08-06-18, 04:08 PM
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I have 2 piping and about 10 feet of head.
 

Last edited by knicks1met; 08-06-18 at 06:45 PM.
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Old 08-07-18, 05:07 AM
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First you need to determine if you can locate your pump below the water level of the lower catch basin. If you can then you can look for a non-self priming pump which will be much more efficient at moving water. If your pump will be located above the water level then a self priming pump would be a better idea but you'll need a larger, more powerful pump to get the same result. in either case you want a pump (not motor horsepower) optimized for moving a large volume of water at low pressure.

Pump design is about trade offs. A pump that can deliver higher pressure generally has lower volume. A high volume pump generally generates lower pressure. Self priming by design is inefficient so there is a penalty in both volume and pressure.
 
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Old 08-07-18, 05:40 AM
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Here is a good discussion on water garden pumps:

How to Select the Proper Pond or Water Garden Pump page 1
 
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Old 08-07-18, 06:36 AM
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Both the 1HP and the 3HP pumps are below the catch basin so it sounds like you're saying a non self priming pump would work better. Since I've already invested in these 2 pumps its kind of what I need to work with now. For the 3HP pump, the best I can do at this point would be to use the largest piping available which would be 3". I also tried going from a 3" to a 2" where the water lets out to create some pressure. It did but still didn't push the water flow down as I hoped.
 
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Old 08-07-18, 07:13 AM
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The speed of flow down the "river" is determined by volume of water per minute, width of the "river", and change in elevation.

You will need to decide whether you want an external pump or a submersible pump.
 
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Old 08-07-18, 07:18 AM
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Originally Posted by Wirepuller38 View Post
The speed of flow down the "river" is determined by volume of water per minute, width of the "river", and change in elevation..
So the change in elevation and the width of the river is something I can not change at this point.

The volume of water I could potentially change I am just trying to determine the best way to do this. I originally thought a total of 4HP through external pumps would be more than enough to give me good flow but it hasn't been.
 
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Old 08-07-18, 07:44 AM
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Old 08-07-18, 08:12 AM
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Originally Posted by Wirepuller38 View Post
But the 3HP IntelliFlo 011018 pump I'm using has a max output of 170 gallons per minute which is 10,200 gallons per hour where the pump you sent is max output of 4,200 gallons per hour.
 
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Old 08-09-18, 01:47 PM
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Any other ideas or suggestions? Do you think it's best to use the 3" line which would create more volume but not as much pressure to push the water down the river or a 2" line where it's higher pressure but not as much volume?
 
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Old 08-09-18, 02:14 PM
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You cannot "push" water down the river. Pressure goes to nothing in an unconfined space like a river. You need more volume. If you are sticking with the pumps you already have then all you can do is improve their efficiency and reduce losses in the piping.

Just as an example at your pump's maximum flow of 170 gpm a 100' long straight piece of 2" pipe will cause a loss of almost 21 psi. Increasing to 3" diameter pipe will reduce the pressure loss to less than 3 psi which is what I'd call the "sweet spot". If you go even larger in pipe to 4" the pressure loss will be less than one psi but that's not much better than 3 so I wouldn't go that big.
 
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Old 08-09-18, 03:32 PM
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Originally Posted by Pilot Dane View Post
You cannot "push" water down the river. Pressure goes to nothing in an unconfined space like a river. You need more volume. If you are sticking with the pumps you already have then all you can do is improve their efficiency and reduce losses in the piping.

Just as an example at your pump's maximum flow of 170 gpm a 100' long straight piece of 2" pipe will cause a loss of almost 21 psi. Increasing to 3" diameter pipe will reduce the pressure loss to less than 3 psi which is what I'd call the "sweet spot". If you go even larger in pipe to 4" the pressure loss will be less than one psi but that's not much better than 3 so I wouldn't go that big.
thank you for that explanation. it was helpful. I guess it seemed like more water was flowing because the 2” caused an increase in pressure immediately where it let out but it sounds like volume would serve my situation better so a 3” line would help.
 
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Old 08-09-18, 03:35 PM
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Originally Posted by Pilot Dane View Post
You cannot "push" water down the river. Pressure goes to nothing in an unconfined space like a river. You need more volume. If you are sticking with the pumps you already have then all you can do is improve their efficiency and reduce losses in the piping.

Just as an example at your pump's maximum flow of 170 gpm a 100' long straight piece of 2" pipe will cause a loss of almost 21 psi. Increasing to 3" diameter pipe will reduce the pressure loss to less than 3 psi which is what I'd call the "sweet spot". If you go even larger in pipe to 4" the pressure loss will be less than one psi but that's not much better than 3 so I wouldn't go that big.
and just curious. you said if i stick with the pumps I have. can you recommend a pump that would work better for my situation?
 
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Old 08-09-18, 04:31 PM
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But the 3HP IntelliFlo 011018 pump I'm using has a max output of 170 gallons per minute which is 10,200 gallons per hour where the pump you sent is max output of 4,200 gallons per hour.
This information would have helped if it had been posted early in the discussion.
 
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Old 08-09-18, 04:40 PM
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Originally Posted by Wirepuller38 View Post
This information would have helped if it had been posted early in the discussion.
I included the brand and exact model along with its HP in my initial post. sorry if i didnt includes its gpm details.
 
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Old 08-10-18, 05:53 AM
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Unfortunately all the pumps I can think of are used commercially or in industry so they are not cheap. On the plus side there are no cheap ones so almost all are of high quality. You need to look at agricultural or industrial applications where moving water efficiently is important. Most will have a pump body with a round spiral shape like a nautilus shell.

Pool pumps and almost any pump intended for residential use will be self priming because it's "easy". And any time things are made for consumers you get the whole range of quality from very good down to garbage. Submersible pumps are often non self priming so there are some good submersible fountain and water transfer pumps. But that brings with it the hazard of having electricity in the water. Any time there is the possibility that people might touch the water I like to keep all AC electricity out of the water.
 
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