Weird "Hollow" Sound - Hayward TriStar VS 950

[drummerman951]

UPDATE: Apparently my neighbor has a small citrus tree that is likely the source of the smell. It is a sickly sweet smell when it is breezy, and I hadn't noticed until I looked over the block wall. I also added a 15 second video of pump at 1328rpm (apx 5psi) so you can hear the sound as well.
Bad Pump Sound Video

Howdy all..
Noticed this today as I was working in the backyard.
*Weird "hollow" sound...
*Faint odor.... Goes away when I turn off pump.
Checked pump basket and skimmer, both free from debris.
Pressure usually 20-21psi @ 3450rpm. Usually run 23hrs @ 1328rpm (4psi) and 1hr @ 3450rpm to clear spa, etc.
Replaced with OEM filters on 2/23/25. Worked fine then with no problems.
Today 26psi @ 3450rpm. Obstruction someplace maybe?

Any ideas before I check cartridges and start running a pig through pad lines? Or should I just call someone based on the faint odor which seems to be coming from pump?
The odor makes me think it is a pump problem, but was new in 2018.
Location: Usually sunny Southern California lol.

Thanks for your guidance!

 

[ajw22]

Filter pressure rise is often caused by algae in the water.

Do a Overnight Chlorine Loss Test. If you fail then follow the SLAM Process

Post a full set of test results from your test kit.

 

[TinFoilHat]

I'm surprised you don't know what citrus blossoms smell like. Around here, that's the sign that spring has sprung.

 

[Poolbreh]

Is your pump basket in correctly? It looks like it’s backwards. The opening in the basket faces the intake.

 

[drummerman951]

Is your pump basket in correctly? It looks like it’s backwards. The opening in the basket faces the intake.

It only goes in one direction. There is a "fin" on the basket that only allows one placement. So that is good. Thanks tho!

 

[drummerman951]

I'm surprised you don't know what citrus blossoms smell like. Around here, that's the sign that spring has sprung.

Dude. I get it. I could have not mentioned it. But around my equipment, it IS a new thing. Because my neighbor NEVER had a citrus plant there. Helpful comments focused on the problem please. Thank you.

 

[drummerman951]

Filter pressure rise is often caused by algae in the water.

Do a Overnight Chlorine Loss Test. If you fail then follow thevSLAM Process

Post a full set of test results from your test kit.

Good point. I will pull cartridges and rinse. They are only a month old. All your other questions are in my signature line. Thanks for the tip!

 

[ajw22]

The most recent tests in your PoolMath log is a month old.

Your FC dipped to 1.5 which gives an opening for algae to get into the water.

If you only test monthly and let FC get that low then you can get an algae problem.

 

[drummerman951]

The most recent tests in your PoolMath log is a month old.

Your FC dipped to 1.5 which gives an opening for algae to get into the water.

If you only test monthly and let FC get that low then you can get an algae problem.

Yeah, I haven't been religious about testing. In season, usually once a week. When it is cold and rainy I usually let it go as long as psi is good and doesn't rise, or other visual indicators. But I have never had this pump sound since installation in 2018, and that concerns me. I will probably have to call out a tech to check pump out. I don't want to replace a pump early! Hopefully no algae problems, but definitely doesn't hurt to check before it is hot everyday. Thanks!

 

[TinFoilHat]

Is it filling the pump basket? The hollow sound could be the pump cavitating due to an air leak. Do you have good flow from your returns?

 

[drummerman951]

Is it filling the pump basket? The hollow sound could be the pump cavitating due to an air leak. Do you have good flow from your returns?

Yes, basket is filling. I'm running it now at 3450 RPM and my PSI has dropped back to 21. I really don't know why it was 26 yesterday. Strong return flow at this time. I'm not going to have a chance to pull the saltwater generator and filter cartridges today, so I'm going to run a super chlorinate and see where I'm at tomorrow afternoon. Thanks for the tip, I appreciate it!

 

[drummerman951]

Here is the current state of the pool at this time… It seems as though the pump sound has become a little more normal, although I don't really know why.

 

[drummerman951]

So on another thread I was having some pump noise, which I think I might ignore for the time being..... but it brought me to another question.... When pool was installed in 2018, I was able to run the pump at 1208rpm and experience great flow for spa waterfall. But now 1208rpm gives only a trickle and I have to bump up to 1300 or so to get the waterfall to be functional.

Provided that all pad equipment is working as it should, what are some possible causes of this situation? The pool currently is not in crisis, no algae, no obstructions at pad piping, SWG or skimmer. Although if I tore apart the pump, I might find the source of my "weird sound" and possibly the answer to this issue as well. I know everything goes from order to disorder, but I am hoping my pump is not getting ready to die after only 5 years. It is bad enough that my Hayward SWG, (which is less than a year old) has decided to no longer read salt accurately. If you are curious about equipment specifics, please review my signature line. And please don't judge my testing habits..... just yet anyway lol.... it has been cold and I am beginning prep for Spring/Summer season.

Thanks in advance for your help!