Will Streamlining my pool plumbing increase efficiency

[danwas44]

Hi,
My GPM for my pump was highly inefficient according to everyone I talked to, and upon doing research found that switching from 90 degree elbows to 90 degree SWEEP elbows should help, and re-plumbing to eliminate unnecessary 90 degree turns would also help. Before I began to re-do the plumbing, I counted 20 90 degree elbows. So today I ripped out all of my above ground plumbing and streamlined it, ended up with 13 - 90 degree SWEEP elbows and 2 - 90 degree elbows (I eliminated 5 elbows completely). As soon as I open up the pool in the next couple of weeks, I'll let you know how much more efficient the plumbing is. I have documented the number of Watts per GPM before I made the changes. I'll run the same test, hopefully it takes less Watts to run the same GPM. Any thoughts if this will work? I've attached the new plumbing photos.

 

[JamesW]

What are your flow rates?

 

[PoolStored]

I have documented the number of Watts per GPM before I made the changes.

Post these for us to give any assessment, include RPMs, Watts and GPM...

 

[Bperry]

Hi,
My GPM for my pump was highly inefficient according to everyone I talked to, and upon doing research found that switching from 90 degree elbows to 90 degree SWEEP elbows should help, and re-plumbing to eliminate unnecessary 90 degree turns would also help. Before I began to re-do the plumbing, I counted 20 90 degree elbows. So today I ripped out all of my above ground plumbing and streamlined it, ended up with 13 - 90 degree SWEEP elbows and 2 - 90 degree elbows (I eliminated 5 elbows completely). As soon as I open up the pool in the next couple of weeks, I'll let you know how much more efficient the plumbing is. I have documented the number of Watts per GPM before I made the changes. I'll run the same test, hopefully it takes less Watts to run the same GPM. Any thoughts if this will work? I've attached the new plumbing photos.

I’m going to guess that there won’t be a measurable difference before and after but that’s just a guess.

Also: Generally the pump manufacturers recommend the inlet and outlet pipes be strait for at least 4x the diameter of the pipe. Looks like your pressure side pipe is lots shorter.

 

[PoolStored]

Also: Generally the pump manufacturers recommend the inlet and outlet pipes be strait for at least 4x the diameter of the pipe. Looks like your pressure side pipe is lots shorter.

I agree they say that, I don't believe it is true on the suction side. See this post:

Is this way too many bends?

I’m getting good suction but don’t know if it would be any better without some of these bends…?

www.troublefreepool.com

I'm not sure on the output side, Pentai Intelliflo manual says to NEVER put a 90 on the input or output. We covered the input above, @mas985 , what are your thoughts on 90s on the output side?

 

[ajw22]

Your heat pump and FNS DE filter is causing more "head" and restrictive inefficiency then all of your 90's and sweep before or after you changes.

Little you can do about that without rethinking your equipment choices.

 

[mas985]

We covered the input above, @mas985 , what are your thoughts on 90s on the output side?

Fittings, in general, really only make a difference to downstream flow and should not affect upstream flow so a 90 right on the output of the pump really shouldn't make any difference at all. In my setup, I have a 90 right on the outlet of the pump to be at the correct height for the filter and it works just fine.

 

[Bperry]

I agree they say that, I don't believe it is true on the suction side. See this post:

Is this way too many bends?

I’m getting good suction but don’t know if it would be any better without some of these bends…?

www.troublefreepool.com

I'm not sure on the output side, Pentai Intelliflo manual says to NEVER put a 90 on the input or output. We covered the input above, @mas985 , what are your thoughts on 90s on the output side?

View attachment 639614

Jandy has it for both intake and output. Maybe they’re unique?

 

[PoolStored]

Jandy has it for both intake and output. Maybe they’re unique?

I was agreeing with you that they all say it.

I was saying, that it really is not true or necessary...there is no issue with 90s into the pump or out of the pump. I gave the link to the input side science and asked mas985 to comment on the output side which he did.

It does not matter with a pool pump if it has 90s as inputs and outputs. Do what you like for warranty purposes, or aesthetics, or your ability to sleep at night.

 

[Bperry]

I was agreeing with you that they all say it.

I was saying, that it really is not true or necessary...there is no issue with 90s into the pump or out of the pump. I gave the link to the input side science and asked mas985 to comment on the output side which he did.

It does not matter with a pool pump if it has 90s as inputs and outputs. Do what you like for warranty purposes, or aesthetics, or your ability to sleep at night.

Ah. I just redid my plumbing to add some length in front of the pump and I find the bubbles are not as prolific, but maybe a coincidence.

 

[ajw22]

Ah. I just redid my plumbing to add some length in front of the pump and I find the bubbles are not as prolific, but maybe a coincidence.

The straight pipe lets turbulence in the water settle down and reduces the bubbles in the water.

 

[JamesW]

Mostly, it will reduce noise and turbulence for water velocity over 6 feet per second, especially when the water contains air bubbles.

Other than that, I don't know about any problems that will be caused by having 90s immediately before or after the pump.

Maybe the people who say that it is such a big deal can post a logical explanation, but it is highly unlikely that that will happen.

Maybe email the people who say that it's a big deal and ask them to explain.

Ask what problems have ever been caused by 90s and ask for specific examples.

 

[JamesW]

Bubbles are caused by suction side leaks.

Other than that, you might get some dissolved gasses coming out of solution at very low pressure at sharp 90s at high velocity.

Cavitation can happen at very high velocity, but that should not be relevant for any properly sized system.

In my opinion, it's a whole lot of concern about nothing.

 

[JamesW]

If 90 degree elbows really were so dangerous and bad, they would not even be made.

If they really were so bad, they would be bad anywhere.

They would be bad before and after long lengths of pipe or short lengths of pipe.

In my opinion, the warnings are ridiculous nonsense.

I am not aware of any example of where a 90 caused any type of significant problem in any pool system where the water velocity was within the guidelines.

I do not even know any hypothesis that is even close to being plausible.

If anyone has any documented examples where a 90 caused a significant problem in any pool system, please provide the case information.

If anyone has any plausible hypothesis that can explain how a 90 would be a problem, please provide it.

 

[JamesW]

Copper pipe is more susceptible to erosion damage and the rule might be applicable to copper pipe especially if the water velocity is over 6 feet per second.

Maybe the rule was developed during the time when many pools were plumbed with copper.

At that time, the plumbing was undersized and the velocity was much higher.

There were probably cases where copper pipe leaked due to erosion caused by excessive velocity and turbulence near 90 degree fittings.

If a pump does not have a strainer basket, then the rule will be relevant to prevent turbulence in the impeller.

Excessive water velocity and turbulence can impact the pump performance and cause cavitation.

However, with a strainer basket and water velocity within industry guidelines, the use of a 90 is not going to affect the performance of the pump or cause cavitation.

 

[danwas44]

I’m going to guess that there won’t be a measurable difference before and after but that’s just a guess.

Also: Generally the pump manufacturers recommend the inlet and outlet pipes be strait for at least 4x the diameter of the pipe. Looks like your pressure side pipe is lots shorter.

Actually I changed that length too. The original pipe was 6 inches long and the pump instructions says 5x the diameter, which I made it to be 10 inches. I actually made it to be 11.

 

[danwas44]

What are your flow rates?

Here are the flow rates

 

[danwas44]

Post these for us to give any assessment, include RPMs, Watts and GPM...

 

[danwas44]

I agree they say that, I don't believe it is true on the suction side. See this post:

Is this way too many bends?

I’m getting good suction but don’t know if it would be any better without some of these bends…?

www.troublefreepool.com

I'm not sure on the output side, Pentai Intelliflo manual says to NEVER put a 90 on the input or output. We covered the input above, @mas985 , what are your thoughts on 90s on the output side?

View attachment 639614

Interesting, I checked my Sta-rite intelliflo manual, and it's very clear on the input side for length of pipe, but says nothing on the output side.

 

[danwas44]

I did some research on Chatgtp, and here is what it said.

The efficiency difference between a PVC 90-degree sweep elbow and a PVC 90-degree street elbow is primarily based on hydraulic resistance, or how much each fitting restricts flow and increases pressure loss in your pool system. Here's a comparison based on equivalent length — a standard method in fluid dynamics that expresses the resistance of a fitting as an equivalent length of straight pipe:

🛠 Equivalent Length Comparison (2-inch Schedule 40 PVC):​

Fitting Type	Equivalent Length	Relative Efficiency
90° Sweep Elbow	~6–8 feet	High efficiency
90° Standard Elbow	~8–10 feet	Medium efficiency
90° Street Elbow	~10–12 feet	Lowest efficiency

Key Points:​

• A sweep elbow has a larger radius, which reduces turbulence and friction loss.
• A street elbow has a short radius and male-female connection, often causing more abrupt turns and greater head loss.
• Replacing a 90° street elbow with a sweep elbow can reduce resistance by up to 30–40% for that individual fitting, which can be significant when scaling across multiple elbows in your system.

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