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2 speed or not

Posted by jasmar (My Page) on
Sat, Mar 17, 12 at 10:40

Ok, looks like it might be time for a motor replacement on my 1.5 hp pentair/pac fab challenger pump. Its about 4-5 years old but lives a hard life due to the forest I call a back yard. Considering a two speed motor. Would that be a good choice for a pool that gets a ton of tree "debris". My concern is that the low speed may not circulate the water fast enough to allow full turn over within 24 hour time period, is there a formula for figuring that out? Pool is about 24-25k gallons. Seems the 1.5 hp 2 speeds have a .5 hp low speed. Seems too small to me. I had a loaner .75 hp motor before replacing the pump/motor last time and it was enough to keep the pool circulated but would not run the pool cleaner (suction).

Follow-Up Postings:

RE: 2 speed or not

Low speed of a two speed pump has half the flow rate of full speed. So turnover takes twice as long.

Depending your plumbing, the full speed flow rate for a 1.5 HP full rated pump will be at least 66 GPM so low speed would be at least 33 GPM.

BTW, I have a 1/2 HP two speed pump and the turnover for my 21k gallon pool on low speed is less than 11 hours.

RE: 2 speed or not

Bear in mind that running on low, if you have an erosion style tablet fed pool will likely have a detrimental effect in many cases. The chlorine normally fed when the water slows down is also reduced and often needs augmenting. While this is not a big deal in most cases, it can get in the way of how you were doing it before. In other words, the motor change is not the only change. Please keep this in mind.


RE: 2 speed or not

Never cared for them myself.....JMO

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