Pool pump upgrade - lower horsepower?


Well-known member
Oct 28, 2017
I have a rectangular in-ground pool, 12'x24' that goes from about 4' deep to about 5'5" deep. Online calculators put it at about 10,000 gallons. The pool is screened in and doesn't get dirty at all. I have no trees that lose leaves or put out pollen or anything.

Currently there is a Century HSQ165 pump installed, it says it's 1.65 horsepower. It runs fine, but I would like to get a variable speed pump to save some $$ on electricity. Pool season is all year round here and I think I could run the pump on low speeds most of the time just to pass water through my solar panels and SWCG. I would bump the speed up for an hour or two a day to run the suction cleaner.

I have a 100 sqft cartridge filter, a Jandy CS100 that I just installed. I have three lines coming into the pump, a 2" line for the main drain which I keep closed, 1.5" for the skimmer, and 1.5" for the suction side cleaner. Going back into the pool is a single 1.5" pvc line going into the ground, I don't know what it looks like after that, but there are three return jets in the pool. No spa or anything special. I will probably be adding a heat pump at the end of the year as well.

That being said, it seems like a 1hp pump would probably be sufficient. I just don't want to make a purchase I will regret and see poor performance from my suction cleaner! Would it be a better investment in my situation to go variable speed, or two-speed?

Also, I prefer to do my own work, is Pentair or Hayward better when it comes to warranties and not using a pool company for installations?

Bama Rambler

Mod Squad
LifeTime Supporter
TFP Expert
Jun 23, 2009
SouthWest Alabama
You'll probably be fine with a 2-speed pump, and if you get a full rated pump a 3/4th hp would be plenty big.

If you want to go with a variable speed you could get by with a 1½ hp.

That's a good question about the warranties. If you install it yourself, Pentair's warranty is 60 days! I like Pentair equipment, but due to that fact, I will never recommend any of their equipment. The last I read, none of the other companies have any restriction on self installs.


Silver Supporter
Gold Supporter
Mar 25, 2018
Chandler Arizona
I personally upgraded my pump to a Hayward Tristar vsp 1-1/2 hp. The savings on electricity are huge. And I have a lot more programming flexibility with that pump. As far as warranty is concerned with Hayward, 1 year if self installed, 3 years if you have a pool company install. I could have easily done it myself, but at that time, I didn’t have the time, so it basically cost me $150 bucks to get a 3 year warranty.
Just my 2 cents.


Well-known member
Oct 28, 2017
I've been looking further into pump replacement and I have some concerns about the dual and VS pumps.

For the dual speed pumps, my concerns are that I can't be 100% sure that a dual speed pump on low will be able to run my SWCG (SJ-40, which I've read takes 30GPM to close the flow switch), purge my solar panels, and run my suction cleaner. Also, I plan to install a heat pump later this year, so I would need enough flow to close the flow switch on that as well. I would also need a new timer to switch between high/lo automatically if say I needed high flow to purge the panels. Even if I was able to run everything on low, would it would enough flow once my cartridge filter started to get dirty?

I like the idea of the VS pumps, I could adjust the speed to make all the equipment happy. My concerns are that it's an expensive item that I'm adding electronics onto that could fail. I need a pro to install the unit if I want to have a full warranty with Pentair or Hayward and that's going to add a lot to the cost when I can handle installing the unit myself. I'm also concerned about lightning/power surges potentially damaging the more delicate circuitry. We have a lot of lightning here in Florida, and I've read sorties on TFP from multiple users replacing their VS pumps that have failed after lightning/surges.

So now I'm wondering if it wouldn't be a better investment to downsize the pump (1.5/1.65hp pump right now) and go with a single speed 3/4 hp pump. Pentair has two 3/4hp pumps I'm eyeing:

Both pumps have the same flow curve according to Pentair's website, so the difference is just energy usage. The SuperFlo 340037 is $307 on Amazon, uses 5.4 amps. 3/4hp with a SF of 1.25. The SuperFlo 348022 (energy efficient model) is $440 on Amazon, uses 4.4 amps, also 3/4hp with an SF of 1.67.

My current 1.5hp pump uses 9.4amps so with either of those pumps I would be saving some money. The 340037 should save me $241/yr, and the 348022 should save me $302/yr at my runtimes.

I'm also concerned about whether or not the 3/4hp is enough, since I would be going with half the rated horsepower of my current pump.

edit: I should also mention that my electric rate is $0.12/kWh, so I'm not sure I can justify a dual speed or VS pump. I need the flow to run all my equipment for 6 hours a day.

edit2: I jumped on an Amazon Warehouse Deal on a Hayward Tristar SP3205EE. 1/2hp single speed pump that uses 4.9amps, so about half what my current pump uses. 87gpm@20 ft head and 62gpm@40ft head. I think it should perform similar to my current 1-1/2hp pump and cost half as much to run. Hopefully it's a good move, and hopefully the pump is not damaged!