When purchasing a new in-ground swimming pool, you need to determine what size pool pump is required. There is a tendency to purchase a bigger pump than what is necessary because people think bigger is better. However, not only does this lead to higher operating costs, but you may also be overpowering your filter system. As a general rule, you should have a pump that filters all the water in a pool in an eight-hour period. This page will show you how to select a pump that filters all the water in your pool in eight hours.
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sendmiller Posted: 6/1/2013
We have a 35,000 in ground pool. We currently have a 1 hp hayward super pump. We have a slide that uses water from the returns to operate. We did not have the pool put in, it was here when we bought the house. Our pump is dying and needs replaced. Local pool store tells us we should have a 1 1/2 hp pump. We are not sure and hesitant to go up for fear this would mess up our system. We have a polaris cleaner but that runs off a booster pump. Can you help recommend if we should stick with 1 hp or upgrade to 1 1/2 hp? Our pipes are 1 1/2 inch if that makes a difference. Thank you for any advice you can give.Reply
InyoPools Product Specialist Dennis R. Posted: 5/29/2013
Alleng - We recommend a 1 1/2 HP pump for an Above Ground pool holding 17,000 gallons of water.Reply
Alleng Posted: 5/27/2013
My above ground pool is a little over 17000 gallons. Not sure how to figure the head on it. i only have one skimmer that is about 4 feet from the pump. My pump died so I'm trying to figure out what would be the appropriate size pump to replace it with. This one was a 1 hp.Reply
InyoPools Product Specialist Dennis R. Posted: 5/23/2013
Bart - We would recommend a 1 1/2 THP pump for your size pool. You have to look at Total HP (THP) when sizing a pump for your pool. THP is equal to HP x Service Factor (SF) as shown on your motor's label. Your old B129 has a THP of 1.95 which was probably larger than you needed. The Tristar EE pump is a good option. I would recommend the 1HP motor (THP 1.85). But a better option, if you can afford the initial cost, is the new Hayward Variable Speed (VS) Super Pump. It is rated at a maximum 1.5 HP. About half the size of the original VS pumps. The initial cost is higher but you can get that back in cheaper operating costs in the first year. And because they are sealed, they will last 2 to 3 times as long as a standard motor. See your guide on How to Save Money Using a Variable Speed Motor for more information.Reply
Bart Posted: 5/22/2013
My pump motor just failed and I've decided it's time to replace the entire pump. The motor was a B129 (AO Smith) 1.5hp that was not the original motor on a Hayward Northstar pump. I have no idea what the original motor was as it failed years ago and a technician replaced it. The pool is about ~17000 gallons with 50ft avg head with a raised spa with waterfall; the filter is a Hayward 4820 DE. Based on what I can calculate, it sounds like the B129 may have been overkill but I'm not sure how to account for the spa and waterfall. I'd like to replace with an EE model and am considering Tristar or equivalent. Do you have any recommendations? Thanks in advance.Reply
InyoPools Product Specialist Dennis R. Posted: 2/24/2013
Frank - In-ground and above ground pool pumps are designed differently. Since an above ground pump is installed below the water level, it can rely on gravity to feed water into the pump. An in-ground pool pump is installed above the pool's water level and is designed to suck water from the pool to the pump.Reply
Frank Posted: 2/22/2013
Why cant you use a above ground pool pump instead of a inground?Reply
InyoPools Product Specialist Dennis R. Posted: 2/11/2013
JayinFL - I would go with a third option, the SP3207EE model - Total HP = 1.39 (HPxSF). This model would deliver the same Total HP as your previous motor. The SP2010EE has a Total HP of 1.85 which I think would be overkill for your setup.Reply
JayinFL Posted: 2/11/2013
OK...here it goes. I have calculated my (kidney-ish) pool at 11,560 gal. Which gives me a turnover rate of 24 GPM. My filter is rated to 127 GPM. I have also calculated the Feet of Head at 47. Using the TriStar charts, it shows I would need a SP3205EE pump. I have a 5 panel solar heating system total run to and fro is 228ft(11ft is vertical to roof) and 4 deck jets with about 102ft of total piping. The existing (fried) pump is a Jandy JHPU1.5 with a 1hp (1.4sf) rated motor. Considering all factors, would I be better off with SP3210EE pump?Reply
InyoPools Product Specialist Dennis R. Posted: 2/11/2013
m.fed67 - With your size pool and no water features or suction cleaner, I would stick with the single speed pump as you suggest.Reply
m.fed67 Posted: 2/9/2013
Hello- I have a 12,000 gal pool with no water features and a dying 3/4hp Hayward pump. I like the idea of an efficient VS pump like the Intelliflo. However since my pool is small, with minimal needs, I would probably run it on the lowest speed all the time so is there really any benefit to having a VS pump? Thank you.Reply
InyoPools Product Specialist Dennis R. Posted: 9/4/2012
ttiger - You have a large pool and if you have other water features, you may need your current size pump. I assume that the pump was sized to your pool. If you are trying to reduce costs, I would suggest looking at a 2-speed or a variable speed pump or motor. See our guide on variable speed motors for potential savings.Reply
ttiger Posted: 9/3/2012
Help please. My pool is 36,0000 gallons. I currently have a Pentair Superflo 2hp which is dying. I need to replace. I want to know if I can get by with a smaller hp pump. I have five solar panels on the roof if that makes any difference, and a freeze defender (not sure if that makes any difference either. Your help is very much appreciated. Also, I have a Polaris pool cleaner and not sure if the hp size affects that.Reply
InyoPools Product Specialist Dennis R. Posted: 7/3/2012
watergirl - We will have to look up your impeller information in our files. Please give us a call.Reply
watergirl Posted: 6/30/2012
For years I had a DE filter, loved it. after it died my pool service company changed over to sand filter, hated it. they changed out the impeller. Now back to DE but not sure my impeller size is correct. Is there any way to determine that? Seems like I have to run longer but never really catch up.Reply
InyoPools Product Specialist Dennis R. Posted: 6/23/2012
Trut,I'm going to have to take another look at our calculations on this guide. Generally for your size pool, 19,000 gallons, we recommend a pump size of 1 to 1 1/2 HP.
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InyoPools Product Specialist Dennis R. Posted: 6/22/2012
Desperate - We would generally recommend a 1 1/2 HP pump for a 19-20,000 gal pool but before you change make sure you have followed the following. If your algae is really bad you may have to shock it twice. We recommend Zappit, http://www.inyopools.com/Products/22300006058112.htm. Also use a good algaecide with the shock treatment: http://www.inyopools.com/Products/22300006058112.htm and finally add Chlorine stabilizer to prevent the sun from depleting your chlorine - aka Cyanuric Acid: http://www.inyopools.com/Products/22300006058077.htm. See our Q&A section under Chemicals for more information.Reply
Trut Posted: 6/21/2012
I have a 16'x32' in ground pool with a calculated gallon size of 19,200. I have calcuated my return line suction at 28 (based on 2 skimmers & 1 main drain all located at the same end as my pump - total length of pipe approx. 85') Based on your formula I could get away with a 1/2 or 3/4 hp motor - is that correct? My current pump was a 1 1/2 hp super pump until it recently burnt out. It sounds like I had overkill with my orignal puump. Now I am concerned as to what size motor I should purchase. Please advise.Reply
Desperate Posted: 6/20/2012
Last year we had a new 1hp super pump installed for our 16x36 in ground pool. We have a green algae problem since this was installed (we have spent a small fortune on chemicals but it keeps returning) Could the pump be to small. Should we replace it with a 1-1/5 or 2 hp pump.Reply
InyoPools Product Specialist Dennis R. Posted: 6/20/2012
bmccormack - For your size pool I would lean towards the larger 1 HP pump.Reply
bmccormack Posted: 6/20/2012
Our existing pump did today. I have been wanting to replace it with a Pentaire efficient pump. Now I HAVE to. Reading all the info is helpful yet still complex. I have an in-ground pool that holds 13,500 gallons of water4 and we use a Pool Pilot salt sy7stem for chlorine generation. From what I am reading I should get a 3/4 horse pump or 1 H/P. am I correct?Reply
InyoPools Product Specialist Dennis R. Posted: 6/16/2012
Yes there is a difference in pump design between an in ground pool pump and an above ground pool pump. Because an above ground pool pumps is installed below the surface of the water, the water is fed into the pump with gravity. An in ground pool pump, on the other hand, is installed above the surface of the pool so is designed to suck water into the pool pump. You will need to get an in ground pool pump and for your size pool I would recommend getting a 1 1/2 HP pump.Reply
Anonymous Posted: 6/15/2012
We moved into a house with a rectangular pool that holds 25,000 gallons of water. Recently, it seems that not much water is filtering through the system. When I went to check the pump it is a 1 hp pump that is supposed to be for an above ground pool. Is there a difference betweem pumps for an inground and above ground pool?Reply
InyoPools Product Specialist Dennis R. Posted: 6/3/2012
atpool - If you have low flow your problem is more likely to be with the pump and suction side that the filter. If your impeller is sound and not clogged, check for leaks in the piping- especially at any unions and valves. Check for blockages in the piping. If you replace the motor, you might go to 1.5 for that size pool. With the new size motor you may need a larger impeller. Also you might consider also stepping up the filter one size to accommodate the larger motor.Reply
InyoPools Product Specialist Dennis R. Posted: 6/3/2012
VB - If you are looking for the most energy efficient Hayward motor, we would recommend getting a Hayward EcoStar Variable Speed pump. They cost more initially but you will recover your initial buy costs in less than a year with significantly reduced (80-90%) operational costs. And it gives you the flexibility to adjust your water flow rate to meet your current problems. See our How to Guide on variable speed pumps for more information.Reply
atpool Posted: 6/2/2012
I have a sta rite system 3 pool filter old style installed in 1997 (PLM150 cartridge) with a 1 hp A.O. Smith pump. The last few years pool water quality has been mediocre not sparkly clear. This season I have had problems with low flow rate so I replaced all o rings and pump gasket. I bought a new cartridge but can't pump water through it only my old cartridge. Does anyone know if they changed cartridge material and would a larger pump say 1.5 hp solve the problem. I have an inground pool 22000 gal.Reply
VB Posted: 6/1/2012
Hello, A really good article. I have a kidney shaped in ground pool with a spa attached (approximately 28000 gallons of water capacity). I also have the caretaker 5 port valve system for water circulation. We are using Hayward 1.5 HP pump at the moment. Every year when we open the pool, the pump does not start initially. a local pool guy told us that we may need to get 2HP pump because of the 5 port valve system. Is it true? If I am looking for a cost effective energy efficient pump, do you recommend Hayward tristar? if so, which one would you recommend?.Thank you so much for the article and information you provided.
-Vik
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InyoPools Product Specialist Dennis R. Posted: 5/25/2012
Jagajak - 2 HP sounds like overkill for a 10,000 gallon pool unless your spa adds 5000 gallons to it. Even if your total gallons is 15K you could easily get by with a 1 1/2 HP motor or convert to a smart pump for circulation.Reply
Jagajak Posted: 5/25/2012
I have a 10K gallon pool with three pumps, one 2HP for water features (rarely used unless I am in the pool) a 2HP pump for general circulation, and a 1.5HP pump as a "blower" motor for the spa..when I use the spa, I use the main pump and the blower pump...its a small pool but an 8 person spa. Question is, to save $$, should I replace the 2HP main with a smart pump, or can I cut the time a day down to 4 hours circulating? I dont want to sacrafice spa force too much but maybe a 1.5 HP motor wouldn't do too much to impact the spa because i have the second motor? Ideas? My goal = reduce cost and maintain some sort of enjoyment of the spa when I want to. :)Reply
InyoPools Product Specialist Dennis R. Posted: 5/22/2012
Poolman2 - Sounds like you could reduce your filtering time in half. I would try that and if your pool doesn't stay clean, raise filtering an hour.Reply
Poolman2 Posted: 5/22/2012
I live in Florida, I have a small pool (8,000 gal), with a 1hp Hayward super pump. I've been running it 6 hours a day for almost 5 years now. I process the water throught the filter approx 3 times a day, what if I just run the pump half the time, wouldn't that be a 50% savings electrically speaking? By your calculations, you feel that the water only needs to be filtered once a day? Correct?Reply
InyoPools Product Specialist Dennis R. Posted: 5/10/2012
tailgate - The typical TDH for most pools your size is 45 to 60 feet. 20 feet sounds way low. Does any of your suction piping run around the perimeter of your pool before going to the pump. Sounds like you have minimal suctions piping, but I would go for a 3/4 HP to be safe.Reply
tailgate Posted: 5/8/2012
My rectangular pool is 16'x34' and is 22,350 gallons. I have calculated that I need a 46.5 GPM pump initially. My pool has one skimmer and the main drain feeds into the bottom of the skimmer box. From there I have another hole under the basket which provides the intake to my pump which is 16-20 ft away. Do I have only 20 ft of head to overcome? I feel like I can get away with a 1/2 HP pump and a filter rated for 50 GPM.... am I calculating this out properly?Reply
InyoPools Product Specialist Dennis R. Posted: 3/19/2012
NADB - The cost of a 2 HP pump on-line is $500-$600 depending on your pump model, so $700 installed doesn't sound that out of line. If you are trying to save money and since your pool is only 15,000 gallons you could replace your motor with a 1 HP or 1 1/2 HP motor - especially if you don't intend to use the Spa. Get a price on-line for both options and shop around for a couple of more quotes for peace of mind.Reply
Not a Dumb Blond Posted: 3/17/2012
My local Leslie's supply co quoted me $700 for a new pool pump. When I bought the house 4 yrs. ago I got a 2 HP (15000 gal rectangular pool with spa/waterfall whose spa I don't use as the heater is broken) for $200. Could pool pumps have really gone up that much. After telling the guy I'm a single mom & can't afford that he told me he'd put a new motor and some other part in mine for $500 & that should be fine as long as I don't use the spa. Am I being taken for a ride & am I better off buying one on line & hiring a local handyman to install it? Thanks!Reply
InyoPools Product Specialist Dennis R. Posted: 2/27/2012
Carpaul5 – Your pump’s total HP (THP) is a product of its HP times its service factor – “SF” on your pump motor label. If your motor’s HP is 2.0 and SF is 1.25, your pump motor is rated as 2.5 THP. If the SF is 1.0, the motor is rated as 2.0 THP. So if your old 2 HP motor has the same SF as your new motor, they are the same. 2-speed pumps run at full speed (3450 RPM) or half speed (1725 RPM). So you might run your filtration system at 1725 RPM for 10 hours and your suction cleaner at 3450 for 2 hours. A variable speed pumps can be programmed for up to 8 speeds with 8 different time slots at any speed between typically 800 – 3450 RPM - for example filtration at 1000 for 8 hours, cleaner at 2500 for 3 hours, spa at 3450 for 2 hours etc. Now the savings: A basic law of physics says if you reduce the RPM by one half from 3450 to 1725, you reduce energy cost to 12.5%. If it costs you $60 a month to run your single speed pump, it would cost you something like $15 a month running a 2-speed and maybe $10 a month with the variable speed. The variable speed is less because you can run the pump at a speed below half for a major portion of your time.Reply
carpaul5 Posted: 2/23/2012
Re: pool pump sizing considering solar panels: you say if I am currently at 1 hp, go to 1.5, but stay at 1.5 if that's what I have. I currently have a 2 hp Magnatek Century Centurion pushing an old Purex Ah series pump. Would a new, energy efficient 2HP motor/pump combo be overkill, or is old 2HP = new 2HP?Also, please explain how variable speed and 2-speed pumps differ and how they achieve the energyy savings over a single speed. (I want to make sure my particular configuration and use patterns would produce savings) - Thanks
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InyoPools Product Specialist Dennis R. Posted: 2/7/2012
Carpaul5 - Roughly speaking, If your current pump is 1HP I would go to 1 1/2. If you are at 1 1/2 now and have an average size pool, I would stay at 1 1/2.Reply
carpaul5 Posted: 2/5/2012
How do I calculate how much extra HP I need for spa, and solar heating panels?Thanks
Paul
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Bobcat Posted: 1/2/2012
Thanks for this information. My pool pump is running just fine now.Reply