New Pump and Motor for an AG Pool

[b2001]

I've got an 18' x 36' above ground pool vinyl pool, a little over 14,000 gallons. I'm looking to replace my pumping system; I suspect that I could get by with less HP and save energy costs. I'd had the pool for 5 years, so it's just a matter of time before either the Pump or Motor will go out anyway. I'm ready to spend the money to realize energy cost savings.

The original Dealer/Installer put in a Pentair Clean and Clear Cartridge System - 150 square foot filtration area, 150 gpm, maximum working presure of 50 psi, and pressure drop at design flow of 8 psi.

They also installed a Purex-Triton Maxim Pump - model number is 39908690, and the nameplace says HP 2.0 SPL, along with an A. O. Smith Motor - BN35, 1.5 HP, rated 230/115 volts and 8/16 amps (115 volt source), and Pump Duty of 1081/1563.

I'm not sure if all of the above information is needed, but better more than less.

I never see Pump/Motor combinations of less than 1.5 HP advertised for above ground pools - my understanding is that these Pumps are self-priming as opposed to in ground pool Pumps. I'd like a better understanding on the importance of that.

Can somone give some advise on what I could go to - hopefully in the 3/4 HP range, how I would figure out how long it would need to run in order to turn the pool water over daily, and maybe suggest some specific brands and models. I'd also like to consider 2 speed models, again with energy savings in mind.

Thanks for any advice ...

 

[duraleigh]

Welcome to the forum! Let's address the pump size first. It's a good rule of thumb to use a pump that will turn your pool (14k) 2-3 times in a 24 hour period....not that your going to run it that much....just it's capacity. So 14k x 2.5 equals (etc., etc.) and it turns out a pump that will produce 25gpm will turn your pool 2.5 times daily. Now that's a small pump!! .5 HP or .75 HP will be plenty. If you want to get really specific, you can go to the website and find the pump curve and calculate your GPM but, from some experience, .5 to .75 HP would be a nice fit for your pool.

The self-priming feature is necessary on inground pumps because they have to "suck" water up to the pump before they can operate. Above ground pool pumps normally don't require self priming because they are below the water level.

I'm not a cartridge filter expert but it sounds like you've got a whopper of a filter.....that's a very good thing. It puts less demand on your pump and should allow for long run times before it needs cleaning.

I don't have an educated opinion on specific brands. Others may and will comment soon.

 

[b2001]

Thanks for the quick reponse and the welcome. I know that I'll also spend some time reading posts here to try to pick up some tips.

It would seem if I don't want to run the pump 24/7, then I would go for above 25 gpm in order to get the same 2 to 3 times turnover of the water, maybe 50 gpm - right?

I will go to the website to look at the pump curves, etc.

I'd like to stay with the same type and size of filter that I now have, since I already have it and am familiar with it from 5 years of use. I didn't have much luck with it when I used bacquacil, but I've had much better luck with chlorine.

 

[duraleigh]

Yeah, if you look at a typical pump curve on a 3/4 hp pump, it'll probably be about 50-60gpm...maybe a little more. That would seem about right for your pool. If you pony up for a two-speed, it would probably be adequate on low most of the time and you'd only use high when vacuuming, etc. There's others here much more precise about pumps than I'm being but I'm in the ballpark.

Secondly, if you're filter is really rated at 150gpm, that's absolutely great for your pool and I'd leave it alone, too. You wouldn't have had luck with ANY filter and baquacil, glad you made the switch to chlorine.