Pool pump Sizing and Feet of Head - Worried too big a pump

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PoolFLPool

Active member
Apr 25, 2022
43
USA
DESPERATE HERE, House for sale, pool inspection in 2 weeks, need to get this right. Recent leak in multiport valve leaves me worried my current 1.5 hp pump is too powerful.

I had recent renovations which replaced all piping to new PVC 1.5" . It previously was very old Poly Pipe mixed with Flex PVC. Before renovation, 1.5 hp pump was working just fine for 19 years. After renovation, I think new plumbing has been so efficient that it increased the GPM of the pumping system due to elimination of possible air leaks in the system. The increase may be too much much. As I understand it, GPM on 1.5" PVC should not exceed 50gpm right ? The specs on the multiport allows up to 60 gpm. The specs on the filter make it clear that it is oversized at allowing 96 gpm (48 sq ft DE Grid Filter) on a 16x32 inground.

I absolutely am mentally fried trying to figure out Feet of Head. All I know is I have about 170 feet of 1.5" PVC in the system not including the elbows, 45's, 90's and the equipment pad with the pump and filter, multiport, and 2 (3 way) valves.

I know I do not want my GPM to exceed 48-50 on my pump because of the limitations of my PVC, right ?

Do you think I should immediately downgrade to a 1.0 hp ? I don't want to risk any damage. Thank you so much. This Feet of Head is so difficult and I have not idea what the current GPM are but I am worried it is more than 60 if the new multiport has a leak although it could also be a defect. Just not willing to take a chance. Thank you.
 
Here are some more specific calculations: (All 1.5 PVC Ridged schedule 40)

Skimmer line: 26' of 1.5 pvc rigid, 5 (45 degrees elbows) , 3 (90 degrees elbows) , 2 (22 degree elbows) , 1 coupling
Main Drain: 30 Ft Poly Pipe, connecting to 14 feet of 1.5 pvc regid, 2 (45's) , 2 (90's) . 1 (22's) , 2 (couplings)
Return line #1 : 69' PVC ridgid, 5 (45's) , 2 (90's) , 5 (22's) , 3 couplings, 1 (T adapter) , 2 Fitting connections, 2 jet reducers/balls.
Return Line #2: 51' PVC rigid, 6 (45's) , 1 (90's) , 5 (22's) , 2 (coulings) , 1 (T adapter) , 2 Fitting conections, 2 jet reducers/balls/
Equipment Pad: Pump inbound 7' above ground rigid PVC, 4 (90's) , 2 (coup) , 2 (Thread adapter) , 1 Union, 2 (3 way valve) , 1 pump, 1 multiportm 1 filter
Equipment Pad: Pump Outbound 9' above ground PVC, 6 (90's) , 2 (Coups) , 1 (Thread adapater), 2 (3 way valves) .

Thank you.
 
What is the pump model?

What is the filter pressure when running?

Equipment Pad: Pump Outbound 9' above ground PVC, 6 (90's) , 2 (Coups) , 1 (Thread adapater), 2 (3 way valves) .
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Does that also mean the pump is 9 ft above the water level? That is very high and I am surprised the pump primes at that elevation.

PoolNJPool said:
After renovation, I think new plumbing has been so efficient that it increased the GPM of the pumping system due to elimination of possible air leaks in the system. The increase may be too much much.
Click to expand...
I doubt that. The air leaks would need to be so bad, the pump would not work.

PoolNJPool said:
As I understand it, GPM on 1.5" PVC should not exceed 50gpm right ? The specs on the multiport allows up to 60 gpm. The specs on the filter make it clear that it is oversized at allowing 96 gpm (48 sq ft DE Grid Filter) on a 16x32 inground.
Click to expand...
Yes that is correct but remember these are recommendations, not hard limits.

PoolNJPool said:
I know I do not want my GPM to exceed 48-50 on my pump because of the limitations of my PVC, right ?
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Again, not a limit, just a recommendation. The pipe will not fail at higher flow rates but the filter could get damaged if flow rates exceed it's limit. The recommendations for pipe come mainly from head loss considerations. Once you get much about 8 ft/sec, head loss gets very high. The suction velocity is recommended to be below 6 ft/sec due to entrapment issues. But it is self correcting in some cases because the pump has a maximum head so it is difficult to get to these velocities with small pipe but it is possible.
 
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mas985 said:
What is the pump model?

What is the filter pressure when running?


Does that also mean the pump is 9 ft above the water level? That is very high and I am surprised the pump primes at that elevation.


I doubt that. The air leaks would need to be so bad, the pump would not work.


Yes that is correct but remember these are recommendations, not hard limits.


Again, not a limit, just a recommendation. The pipe will not fail at higher flow rates but the filter could get damaged if flow rates exceed it's limit. The recommendations for pipe come mainly from head loss considerations. Once you get much about 8 ft/sec, head loss gets very high. The suction velocity is recommended to be below 6 ft/sec due to entrapment issues. But it is self correcting in some cases because the pump has a maximum head so it is difficult to get to these velocities with small pipe but it is possible.
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Further Clarification and thank you. Current pump is Hayward 1.5hp, 1.5 inch PVC. The 9 feet above water is poor working by me. What I meant to say is that I have about 9's of PVC above the ground at the equipment pad. The actual height above water level is about 2 feet. Filter pressure is currently about 12 psi and that is typical. When it gets to 19, I backwash. Because filter is so big, I only need to backwash 1-2 times max per season. My goal here truly is to make sure that my 1.5 HP is not too powerful for the multiport valve or other parts of the system. The pool equipment pad is very close to the finshed basement window and I do not want a flood if something blows. The multiport valve says it has a 60 gpm max rate so I really want to avoid the actual pump flow rate being too high here. Although there remains a possibility that the leak that began this week was due to valve defect, just want to make sure I am not passing on a problem to the buyer, cause I care as a seller, haha. Do you think I sure purchase a flow meter and install to measure the exact current GPM flow rate ? As far as the feet of head, still clueless on what the actual number is. I hear the typical pool is 30 ? God Bless you for helping me. You have no frinking clue how much I appreciate it. Thank you.
 
PoolNJPool said:
Current pump is Hayward 1.5hp, 1.5 inch PVC.
Click to expand...
That doesn't tell me much. I need to know the exact model of the pump. If you don't know, post a picture.


PoolNJPool said:
The 9 feet above water is poor working by me. What I meant to say is that I have about 9's of PVC above the ground at the equipment pad.
Click to expand...
Still don't know what that means. "9's"? You mean there is ~9' of PVC pipe above ground?

PoolNJPool said:
The actual height above water level is about 2 feet. Filter pressure is currently about 12 psi and that is typical. When it gets to 19, I backwash. Because filter is so big, I only need to backwash 1-2 times max per season. My goal here truly is to make sure that my 1.5 HP is not too powerful for the multiport valve or other parts of the system. The pool equipment pad is very close to the finshed basement window and I do not want a flood if something blows.
Click to expand...
A pool pump does not have enough power to make the plumbing or filter "blow up". 12 PSI is pretty low in terms of pressure so that is not an issue. It also indicates that the flow rate is not all that high either.

PoolNJPool said:
The multiport valve says it has a 60 gpm max rate so I really want to avoid the actual pump flow rate being too high here.
Click to expand...
Even that is probably not a big deal if exceeded. Again, these are recommendations, not limits.

PoolNJPool said:
Do you think I sure purchase a flow meter and install to measure the exact current GPM flow rate ?
Click to expand...
I wouldn't bother. I can get close enough if you give me all the details (i.e. pump model).
 
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mas985 said:
That doesn't tell me much. I need to know the exact model of the pump. If you don't know, post a picture.



Still don't know what that means. "9's"? You mean there is ~9' of PVC pipe above ground?


A pool pump does not have enough power to make the plumbing or filter "blow up". 12 PSI is pretty low in terms of pressure so that is not an issue. It also indicates that the flow rate is not all that high either.


Even that is probably not a big deal if exceeded. Again, these are recommendations, not limits.


I wouldn't bother. I can get close enough if you give me all the details (i.e. pump model).
Click to expand...
Hmmm I responded, must have not posted, uggh, ok here we go.

1. Pump is a Hayward Super Pump 1.5hp, 1.5 PVC, Model# SP2610X1.
2. Yes, there is 9' of PVC total in the equipment pad area on the outbound pressure side leaving the Filter. There is 7' of PVC total on the inbound suction starting at pump entrance up to the filter entrance. I hope that makes sense.
3. The filter itself if I did not already say it is a Hayward DE 48 sq feet, model DE4820 with a 96 gpm Design Flow Rate.
Thanks you.
 

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Operating point should be close to 59 GPM @ 56' of head. So no worries.

The above is with one of the two suction lines. With both open, the operating point becomes: 66 GPM @ 53' of head. Still nothing to get too concerned about.
 
Is there a problem with your current 1.5HP pump that requires its replacement?
 
mas985 said:
Operating point should be close to 59 GPM @ 56' of head. So no worries.

The above is with one of the two suction lines. With both open, the operating point becomes: 66 GPM @ 53' of head. Still nothing to get too concerned about.
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Ok thank you for everything. This is all so confusing with this head stuff, way too complicated. Do you recommend that I install a gpm flow rate tester to monitor ? I always have had both suction lines operating with 1.5 120v superpumps.
 
ajw22 said:
Is there a problem with your current 1.5HP pump that requires its replacement?
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I have always had it and a multiport without issue. The multiport body and Top handle lid was changed this week. About 5 days later a small leak appeared on the mold injector point on top. I suspect it is a defect in the manufacturing pricess because it never had that happened with the previous one which the lid was only 6 months old but body was much older. I just wanted everything new do I had the entire assembly put it new.
 
PoolNJPool said:
Ok thank you for everything. This is all so confusing with this head stuff, way too complicated. Do you recommend that I install a gpm flow rate tester to monitor ? I always have had both suction lines operating with 1.5 120v superpumps.
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James, just one follow up question. If I downgrade to a 1 hp, will thay be a gopd option ? Will doing so negatively impact suction and water flow ? I assume it will reduce GPM ? Part of me just would feel more confortable. Tye Hayward Super Pump 1hp though requires 2" piping going in and out it says. What do you suggest I do in that case ? Thanks.
 
If you want to change pumps then get a VS pump and then you can run it at whatever HP turns out to be best.

You don’t need to do all this guessing and calculating and estimating. Just get a VS pump that gives you variable HP.
 
PoolNJPool said:
James, just one follow up question. If I downgrade to a 1 hp, will thay be a gopd option ? Will doing so negatively impact suction and water flow ? I assume it will reduce GPM ? Part of me just would feel more confortable. Tye Hayward Super Pump 1hp though requires 2" piping going in and out it says. What do you suggest I do in that case ? Thanks.
Click to expand...
What in the leak report indicates a pump problem? If the pump is sound and you're that concerned about flow, install a new .75hp impeller, a shaft seal, body gasket. Pump will become a .75hp regardless of motor size and it will be much less expensive. There are, literally, thousands of those pumps on 1.5" plumbing without issues. Your pump, downsized to .75hp this way, will give good circulation, and be able to backwash the filter well, and save you money.
 
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In my opinion, you don't need anything more than the smallest Superpump.

If you want a new pump, I would go with a SP2600X5.

If you just want to reduce the flow, I would go to a SPX2600C or a SPX2605C impeller.

Hayward Impeller 0.5 THP - SPX2600C - INYOPools.com

SPX2600C - IMPELLER, SP2600-C HAYWARD (SPX2600C)
www.inyopools.com www.inyopools.com

Hayward Impeller, 0.75 THP, Hayward Super Pump, MaxFlo, Super II - SPX2605C - INYOPools.com

SPX2605C - IMPELLER, 1/2-3/4 HP,SP2605-C (SPX2605C)
www.inyopools.com www.inyopools.com

Impeller...........Total HP required.
SPX2600C............0.60
SPX2605C............0.75
SPX2607C............1.10
SPX2610C............1.50
SPX2615C............2.00


1657999543678.png
1657999498519.png


Hayward Super Pump 1/2 HP Single Speed Swimming Pool Pump - INYOPools.com

Hayward Super Pump - The best swimming pool pump on the market
www.inyopools.com www.inyopools.com
 
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