Normal Pump Pressure

Sep 2, 2011
63
Nanty Glo, PA
New pool owner here. I'm questioning my filter pressure and wondering if it seems "normal". I understand there are probably a lot of factors that determine "normal" pressure. I have a brand new above-ground pool 24' x 52" with 1 skimmer and a main drain (normal 2 8" round drains about 5' apart in the bottom center). Plumbing is run with the normal bundled 1 1/2" flexline (main drain uses 1 1/2 flexible PVC). I forgot to grab the model name / number off the pump & filter, but it appears I have these (browsing Hayward's website):

Filter: Hayward Sand Filter - Pro Series Top Mount

S180T1580S.jpg


Pump: Hayward Power-Flo LX (I remember mine was labeled 60 GPM & 1HP)

PowerFloLX.jpg



Ever since the initial install my filter pressure gauge reads 11psi when clean (ie. when initially setup & immediately after a backwash). By the time it reaches 13psi the flow out of the return seems greatly reduced and so I backwash (this ends up about every 2 or 3 weeks I guess). When I switch between main drain only or skimmer only the pressure remains about the same; I think on main drain only it might drop to about 10.5psi. The water circulation appears to be very good (when filter is clean, running 11psi); I can see the whirlpool effect.

Does this sound normal? I read of others with much much higher pressure readings.

Thanks,
Garry

P.S. I've added my first jug of good ol' bleach this past week! I'm on my way to converting to the BBB!
 
I have a DE filter, so my experience may not be totally relevant, but my filter pressure right after cleaning the filter is 11-12 psi, and I have also experienced the same phenomenon where after a few weeks the flow out of the returns will diminish (not severly, but enough for my "calibrated" hand to notice), but the filter pressure only climbs about 2 psi.

So, I would say your situation is normal.
 
The flow from a pump can change dramatically when the filter gets dirty. A 2 PSI rise in the filter is close to 5' of extra head. That can be enough to reduce the flow rate in a pump (especially AG pumps).

This is why I believe the common industry recommendation to clean a filter at 8-10 PSI rise is far too long to wait between cleanings. On the other hand, it is really up to the PO to determine how often they are willing to clean the filter as well. This is why the forum in general recommends large filters so that the PSI rise is kept low while increasing the time between the cleaning.
 
I have a sand filter and my pressure is about the same (11psi). I can tell a reduction in flow before the pressure rises the recommended 10 psi. I think a better backwash indicator is 25% of the clean filter pressure. At 11 psi that would be 3 psi rise and that agrees with your experience.
 
In the past (using 1.5 HP pumps) - I have usually gone about 5 PSI over normal or whenever I vacuum the pool before I backflush.

When I was using a Powerflo II 3/4 HP for 2 weeks this summer - I didn't have a strainer on it so i tried to avoid backflushing.
 
Ok, thanks for all the quick replies! Glad to hear my situation is pretty normal. I do think the pool contractor who did the install & "training" (if you call it that) told me some blanket statement like "when the psi rises 8 to 10 backwash". Then I started feeling such a reduction at just 2 to 3 psi that I didn't think I wanted to wait until 8 to 10! Learning that I can't trust "the pool guys", at least not without verifying that they know what they are talking about!

Thanks,
Garry
 
garrybunk said:
Ok, thanks for all the quick replies! Glad to hear my situation is pretty normal. I do think the pool contractor who did the install & "training" (if you call it that) told me some blanket statement like "when the psi rises 8 to 10 backwash". Then I started feeling such a reduction at just 2 to 3 psi that I didn't think I wanted to wait until 8 to 10! Learning that I can't trust "the pool guys", at least not without verifying that they know what they are talking about!

Thanks,
Garry

I'd put it more as "Trust but verify".. :cool:
 
I really like the posts above by mas985 and bama rambler. I agree that a 25% increase from normal clean filter psi is a good indicator to backwash/clean and I think 8-10 psi is way too long....especially if your clean psi is around 10 as many of us expereience.
 
Update - I just opened up my pool this past weekend and my pump is now running at 15psi. I did backwash the filter and rinse but it remained at 15psi. There is no difference in the plumbing from last year to this year, so why would my pump pressure differ?

-Garry
 

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Ok, I looked at my gauge last night and it was right on "0" when off and up to 15 when running. By the way, I didn't change the sand out in the filter or anything between winterizing and opening up. I just simply drained the filter and removed the control valve for winter and replaced the valve last weekend and turned it all back on. The sand was only used one season.

-Garry
 
When you have pretty good balanced water and the pool is sparkling clean can it be normal to NOT have to backwash for quite a while ? My clean pressure is around 16 and only increased by 1-1.5psi over the past couple weeks...Just curious if possibly something else is going on, or maybe its just that my pool is real clean since on the BBB plan :) ??
 
After reading a little bit about the pressure readings that should be normal I think my pressure is too high. I'm not sure if the high number 25 PSI after backwash and rinsing DE grids is normal. I get good flow out of the 3 returns. I have 2 main drains connected to the same pipe and 2 skimmers. The far skimmer from the pump seems like it has less draw then the other one. My pump is about 25 feet from the pool about 4 feet about the water level. When I run the pump to waste the pressure goes down to the 10 PSI everyone else is getting as normal. I have a hayward heat pump after the filter and a SWC after that, then it goes back to the pools 3 returns. What does the high pressure mean? Should I be concerned? This is not the origional pressure gauge but it does go back to zero when the pool is off. The gauge is on top of the filter.
 
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