Advice for Pump for 20K pool with solar

Hi folks,

I think I’m looking at replacing my 12 year old Pentair WhisperFlo WFE-6 and am kind of at a loss regarding what is the right replacement and you’ve steered me right before, so am again seeking any advice you might have for me.

Specs for my pool:

21,000 gal in-ground pool (14’ x 27’ av. depth 7’ [3’ shallow/11’ deep] with 8’ circular spillover spa 4’ depth at a 2’ rise from the pool)

both spa and pool were completely replastered 5 years ago, but the pool was built in +/-1980.

Heliocol roof-top solar (at 15’ rise from pool, 23’ from pump)–panels to 100% of pool surface area

GL-235 goldline solar  controller

ancient manual timer for pump on/off

12 year old pentair WhisperFlo WFE-6 1.5hp pump

Brand new pentair CCP320 cartridge filter

Hayward Navigator sweeper in-wall

Standard skimmer with fail-out to bottom drain

3 pool return jets

All above-ground plumbing and solar plumbing is 2” PVC but we are assuming the “hidden” pipes are 1.5” copper, given the age of the pool.

During the swimming season here in coastal San Diego (mid April though end of November) the pump runs for the full solar day, 10 am to 50 / 6:00 pm) and is off the rest of the time (I keep the pool between 87° and 95° - yes, I’m a wimp, I hate cold water). In the off season, when we’ve gotten past my ability to keep it at those temps, I throttle back and it runs for 4 to 4.5 hours a day (the minimum to keep the pool clean/algae free).

This pump has always been noisy (definitely not the Whisper of its name), but it is now just intolerable. It’s been rebuilt 3 times (new bearings, etc.) but I think this may be the end of the line, because even rebuilt, the thing is twice as noisy as the 2 hp pump that runs the spa and everyone tells me the new pumps are quieter, so I’m looking at putting in a new pump and seeking your advice.

I’ve looked at various forums and articles and much is made of how much a VS pump saves in terms of money because you can run it at lower speeds. I can see that for the 4 months of the non swim season, I could benefit from this, but, don’t really know if this would be of any value during the swim season because I am maximizing every moment of runtime to run the pump to heat the pool, and I seem to understand that I can’t do that at a “lower speed” so that would put me still running full out at the only time I can to run it  for heat . When its running full out, 7.5 hours a day, I don’t need to run it any more hours to keep it clean, so I’m guessing I wouldn’t be running it after “suntime” and thus not using anything but the one speed.

But I could be wrong. I’m pretty much at sea. I’m looking for quiet pump and a hot pool during the swim season. I had been impressed by what your folks had said about the Speck pumps, but others tell me I should stay “all Pentair” even though they’re much more expensive. Now I’m just feeling paralyzed. Do you have some suggestions for me?

Thanks for any advice you could give me,