PSI Dropped to 6 from 10 after Pool Revamp

[EllieWilliams]

Weirdest question I think I have ever presented to you all -

Just finished a revamp on my 40 year old pool - new cooping, tile and surfacing (drain hole plugged). Replaced pump and motor for prosperity, as well. Cleaned and replaced the filters. Everything is clean, clear and running really well, inlet valves are pushing water with no air - so I am scratching my head and thinking how can my filter psi be only 6 when it has been running 9 for years - could the revamp have brought the old gal back to a new norm?

1) for the last 10 years running at a consistent 9-10 psi - now 6 psi
2) new revamp gave me chip out and brand new inlet valves
3) troubleshot all the causes for low psi - water level perfect, clogs in skimmer, piping, etc, double checked all the connections, 0-Rings replaced with pump (but double checked), etc. - but nothing is a problem (assuming gauge is still working)
4) history of plumbing: a) replaced skimmer 5 years ago; inlet valve leaks 7 years ago resolved; motor replaced 10 years ago (prior to this new one)

Pool is 75 feet perimeter, 4 inlet valves, 1 skimmer, with 1-1/2 in PVC piping and only a 1 HP pump and filter connections (see pic), pretty simple.

Thoughts

 

[mknauss]

Same exact pump? Or did you just replace the motor? Does the gauge go to zero when the pump is off? Does tapping the gauge do anything?

 

[JamesW]

Is the pump the exact same make, model and HP?

 

[EllieWilliams]

Same exact pump? Or did you just replace the motor? Does the gauge go to zero when the pump is off? Does tapping the gauge do anything?

Exact same pump and motor (make, model, size, and manufacturer) Harris Above Ground & In-ground Pumps 152716;
Yes, does go to -0- when turned off; and
Tapping does nothing off or on, steady as is.

 

[EllieWilliams]

Is the pump the exact same make, model and HP?

Exact same pump and motor (make, model, size, and manufacturer) Harris Above Ground & In-ground Pumps 152716

 

[borjis]

That is a bit odd.

I had a few psi rise going from a Jandy 250k btu heater to a Raypak 266k btu heater.
Which was sort of half expected.

 

[setsailsoon]

Brand new filer cartridges? That's a lot for new cartridges though. My guess is that even though the pump and motor are duplicates maybe the pump has been improved somewhat and you now have a different performance curve or you had damage internal to the old pump and didn't know it.

 

[EllieWilliams]

That is a bit odd.

I had a few psi rise going from a Jandy 250k btu heater to a Raypak 266k btu heater.
Which was sort of half expected.

And the pool plaster stated that it is not the first time that an operating system dropped in PSI, especially on the older pools with all original innards. Could it be that by closing the drain (the skimmer was replaced due to the drain connection there disconnected and caused a major leak, so it was closed at skimmer) and replacing the inlets may have tightened up everything to cause less friction?

 

[mknauss]

Most likely due to a number of factors. More efficient plumbing, slightly different pump curve, etc.

I do not think it is anything to be concerned over.

 

[Jimrahbe]

Ellie,

Just so that we are all on the same page... Low filter pressure is better than a higher filter pressure as long as the water flowing back to your pool is the same.

Filter pressure is the amount of effort it takes for the pump to force the water through the filter and plumbing... The less the filter pressure the more flow you will have.

I have a VS pump that I run at about 1200 RPM and my filter pressure is only 1 or 2 lbs. and my pool works just fine.

I think that you are worrying over nothing..

Thanks,

Jim R.

 

[EllieWilliams]

Brand new filer cartridges? That's a lot for new cartridges though. My guess is that even though the pump and motor are duplicates maybe the pump has been improved somewhat and you now have a different performance curve or you had damage internal to the old pump and didn't know it.

Oh, no, nothing changed on the filter same one, just changed out the filters themselves to start with a clean slate, it is solid as a rock. Filter: Pac-Fab (Pentair) Mytilus MA-90C Cartridge;

 

[EllieWilliams]

Ellie,

Just so that we are all on the same page... Low filter pressure is better than a higher filter pressure as long as the water flowing back to your pool is the same.

Filter pressure is the amount of effort it takes for the pump to force the water through the filter and plumbing... The less the filter pressure the more flow you will have.

I have a VS pump that I run at about 1200 RPM and my filter pressure is only 1 or 2 lbs. and my pool works just fine.

I think that you are worrying over nothing..

Thanks,

Jim R.

Jim, this is the best thing I could hear, as I am sure subconsciously I had come to the same conclusion days ago. It is so hard to see something new when everything was so different for so long. I believe I have over thought the new pool process and my system. I shall let the process complete and enjoy my new (used) pool.

Thank you all for your input and reassurance to the thought process, makes me sure I am coming to the same conclusion. Have a wonderful Easter and enjoy.
Ellie

 

[cfherrman]

What about your pressure guage? Does it have a air bleed on it? Did you bang things around where the guage is while changing filters?

 

[EllieWilliams]

What about your pressure guage? Does it have a air bleed on it? Did you bang things around where the guage is while changing filters?

I did, always bleed air gauge from filter after any maintenance on the filter unit, this was no different. I fact since this issue, did several times. Thank you.