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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Chris Posted: 6/3/2016
So for variable speed pumps is the HP rating not important due to the ability to change speeds? I'd really like to go with a variable speed pump to get the most efficiency. We have a lot of trees around the pool so it's going to be running quite a bit.Reply
InyoPools Product Specialist Dennis R. Posted: 6/2/2016
Chris - For your size pool and water accessories, I would recommend one of two size pumps. If you have 1 1/2" piping, I'd go with a 1 1/2 HP pump. If 2" piping, go with a 2 HP pump. One pump should be able to handle your pool requirements. We have a series of new pumps we are recommending for quality and savings: the PureLine Pure Water Pool Pump 2 HP -PL3503 and the PureLine Pure Water Pool Pump 1.5 HP - PL3502. There is some confusion in the HP descriptions. The PL3503 is 2 HP not 1 HP, and the PL3502 is 1 HP not 3/4 HP.Reply
Chris Posted: 6/1/2016
I've got a 20,000 gallon pool, with roughly 35' of head, a waterfall and a pool sweep. It has a Hayward C4025 filter and some really old pumps (made over 20 years ago). Can I use one pump? What size would be ideal? I can post photos if necessary.Reply
InyoPools Product Specialist Dennis R. Posted: 5/31/2016
6000-gallon pool - Here a link to a VS pump that would better suit your small pool needs: Hayward Super Pump VS Variable Speed Pump (115V) 0.85 HP. If your pool system needs a stronger pump for jets, water features, look at this new Prime Variable Speed Pool Pump 1.65 HP. Great quality and price.Reply
InyoPools Product Specialist Dennis R. Posted: 5/31/2016
BM11 - For your ~26,000-gallon pool, I would recommend a mid-size VS pump like the new PureLine Prime Variable Speed Pool Pump 1.65 HP.Reply
Anonymous Posted: 5/30/2016
Hi. I have a small 6000 gallon pool and I need to upgrade to a variable speed pump. I've been told that I can't just upgrade the motor but that it needs a whole new pump with pipes etc. He is recommending the Pentair Intelliflo 2 vst(?) which he says is the new one that they're selling. I'm trying to do some research and I'm seeing that the Intelliflo has a 3hp motor. Is this correct and if so why would he be suggesting such a large hp for my small pool? Does Pentair Intelliflo make a 1hp-1.5hp vs motor?Reply
InyoPools Product Specialist Dennis R. Posted: 5/30/2016
Susan - Susan - The humming you hear from your motor is most likely due to the start capacitor going bad. To check this capacitor and possibly replace it, see our guide on “How to Replace a Pool Pump Capacitor”. For you size pool, I would stick with the 1 hp pump/motor.Reply
InyoPools Product Specialist Dennis R. Posted: 5/30/2016
Motor humming – The humming you hear from your motor is most likely due to the start capacitor going bad. To check this capacitor and possibly replace it, see our guide on “How to Replace a Pool Pump Capacitor”.Reply
InyoPools Product Specialist Dennis R. Posted: 5/30/2016
Dave – Do you have diverter or ball valves to regulate water flow to your waterfall or are they taking the full pressure from your 2 HP pump. If the water flow is not being regulated and you replace the 2 HP pump with a 1 HP pump, will you be satisfied with half the waterfall length? If they are being regulated, how close are the valves to being fully open? Half way would be equivalent to a 1 HP motor.Reply
BM11 Posted: 5/28/2016
Hello , I have an 18x36 in ground rectangular pool. 3ft-8ft. What size HP variable speed pump should I buy?Reply
Susan Posted: 5/25/2016
Have a 20000 gal inground rectangular pool - currently have a Hayward Super Pump HP 1. Currently hums and then blows breaker. Would a 3/4 hp 115 pump work for me?Reply
Anonymous Posted: 5/25/2016
I have a 20000 gallon rectangular pool with 1 skimmer. I currently have a Hayward Super Pump that just hums and then blows my breaker. Could this be a short in the pump?Reply
Dave Posted: 5/24/2016
Thanks, Inyopool!Second question. I have the same 2hp Northstar pump for my water feature, which is 2 - 18" slit waterfalls. I think that is overkill as well. Since it's only a feature with no cleaning or filtering duties, could I use a 1hp single speed? While I can look at the pressure gauges (filter and pump), not sure how I could determine the needed HP necessary so that I still have waterfalls and not just trickles, especially since I will most likely have to do some PVC re-routing for a smaller pump.
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InyoPools Product Specialist Dennis R. Posted: 5/23/2016
john mac - For your size pool with spa, I would definitely go with the larger 3.0 HP VS motor.Reply
john mac Posted: 5/22/2016
I currently have a starite maxi glass II, 2hp pump . 22000 gal pool with attached spa... I want to replace with variable speed motor. Looking at eco tech motor . Should I get 1.5 hp or 3.0 hp?Reply
InyoPools Product Specialist Dennis R. Posted: 5/10/2016
Dave - Generally a 2 HP pump is larger than you need for a 13,000 gallon pool. I would go with the 1.5 HP VS pump.Reply
Dave Posted: 5/10/2016
I have a 13,000 gal salt pool with attached spa. Drain, skimmer and pool sweep. Currently running 2hp Hayward Northstar. Want to get a variable speed to try and save on electricity. Do I need a 2hp, or would a 1 or 1.5 suffice?Reply
InyoPools Product Specialist Dennis R. Posted: 5/9/2016
Steve - No, you do not need to make any other system upgrades to convert to a VS pump. It is a relatively easy process.Reply
InyoPools Product Specialist Dennis R. Posted: 5/9/2016
Homerun - If you downsized your motor from 1 HP to 3/4 HP without changing the impeller, you may be overloading your motor severely. The impeller is trying to move as much water as it did with a smaller motor. Check if you need a smaller impeller, and if so, replace it. Or, for your size pool, a 1 HP motor is generally what's required to move that much water. You might consider going to a 1 HP motor.Reply
InyoPools Product Specialist Dennis R. Posted: 5/9/2016
Willis258 - Sound like you have a 30,000 gallon pool. I would use 2" or 2 1/2" pipe where you can. Also, for your size pool, I would consider a large variable speed pump. You can save up to 80% on operation costs. Here is a guide on what you might consider for the circulation function of your pool - "How To Set Up In Ground Pool Equipment - Part 1 - Circulation".Reply
Steve Posted: 5/8/2016
I currently have a single speed pump. Can I replace it with a variable speed pump or do I need to make addidional upgrades to the system?Thanks,
Reply
Homerun Posted: 5/8/2016
I have a rectangle pool 14w30long from 3ft to 9ft 3/4 motor was just put in ,,But the fanblade was not changed so some times it runs strong & other times very sluggish,,there is a small leaf floating around for 4 days it don't have enough thrust to move it to the skimmer so what do i do ??Reply
Willis258 Posted: 5/7/2016
What size pump should I use on a 20x40 with 6 returns aND 3 step jets, also should I use 2 inch pipe for the skimmers I have a 50ft and 70fy run on the skimmers to the pump.Reply
InyoPools Product Specialist Dennis R. Posted: 5/4/2016
Windy Miller - Sounds like your proposed pool size is just over 100,000 gallons. So you are going to need as large a pump and filter as you can get. And you may want to split your pool functions into two systems: one for basic circulation and one for water features. See our guide on "How To Set Up In Ground Pool Equipment - Part 0 - Overview". This series of guides was based on a 30,000 gallon system so you may have to get larger equipment or run it longer. I would get the largest Variable Speed Pump you can find like the Sta-Rite INTELLIPRO VARIABLE SPEED ULTRA ENERGY-EFFICIENT POOL PUMP. On the cartridge filter, look for maximum sq. ft. filtration and GPM flow like the Jandy 4-cartridge system shown in the guide.Reply
Windy Miller Posted: 5/2/2016
I am building a pool 82 x 33 x 5 ft - from the formula it comes out to a flow rate of ~211 GPM to filter water in 8 hours. What size of pump, filter(s) and pipe do you recommend? I would very much appreciate some advice. Thanks WindyReply
InyoPools Product Specialist Dennis R. Posted: 4/19/2016
les gideons - Here's a link to our best priced 2 HP in ground pool pump - PureLine Prime Pool Pump 2 HP. Shipping is free. Total cost is $399.Reply
les gideons Posted: 4/19/2016
price of a 2 horse in ground pool shipping price included. thanksReply
InyoPools Product Specialist Dennis R. Posted: 4/14/2016
lovesbiddy - I would replace your current pump with one that has the same HP and SF. See our guide on "How To Understand True Pump Horsepower - Up Rated vs Full Rated". Pool heaters will shut off at 20 to 40 GPM depending on the make and model of heater.Reply
lovesbiddy Posted: 4/13/2016
We have a pretty old pool but it is new to us as we just purchased this home. It does not have a bottom drain, only has 2 jets and 1 skimmer. We would like to replace the pump on it and by the calculations you have shown we need one with 51 GPM and just one skimmer at approx. 45 ft of head. Does the fact that it doesn't have a bottom drain create any extra issues? What about the pool heater, does it need to have the same flow requirements like the filter?Reply
InyoPools Product Specialist Dennis R. Posted: 4/13/2016
LuvMahPool - It sounds like most of your piping is 1 1/2" so I wouldn't go with a much larger pump. Variable speed is good. You can recoup most of your initial cost with an up to 80% reduction in operating cost. For a great price on great quality, I would recommend the newer "PureLine Prime Variable Speed Pool Pump 1.65 HP".Reply
LuvMahPool Posted: 4/11/2016
I recently bought a house with a pool. I'm a first time pool owner. The pool is 36,000 gal. I have two skimmers connected in series through one 1 1/2"(65' long) pipe to valve where it connects to the drain 1 1/2" (38' long) line. These are joined to one 2" (2' long) line to the pump. All the rest of the plumbing is 2" line until it get to the ground to return to the pool via the three jets. There, I split the 2" line to use the existing 1 1/2" (38' long) pipe to the three jets and also use the 1 1/2" (30' long) line to the Polaris (no longer used). I am now using this line as a fourth jet. My pump is a 1 1/2hp single speed pump and my flowmeter shows 70gpm, filter pressure is 20psi. Would I benefit from a larger pump on a variable drive or would the savings be negligible?Reply
InyoPools Product Specialist Dennis R. Posted: 3/18/2016
scpoolguy - I would recommend a 1 HP pump with 2" piping.Reply
scpoolguy Posted: 3/15/2016
I am looking to build a 14x28 rectangle, around 12,500 gallons, 1 skimmer, main drain,3 returns, 2 step jets. Based on wind direction and where I would like to locate my pump and filter I am looking at about 70 feet of pipe from the pump to the skimmer and about 65 feet of pipe to the main drain.My questions are=
1. What size pump should I use?
2. What size piping should I use?
Reply
InyoPools Product Specialist Dennis R. Posted: 3/7/2016
Wai Kane - Glad to help. If you have a rectangular pool, you multiply the pool's length times it's width times its average depth. That will give you your pool's cubic feet. There are 7.5 gallons of water in a cubic foot so multiply your pool's cubic feet by 7.5 to determine its total gallons. See step 1 of this guide for an example of this calculation. GPM is Gallons Per Minute. You get this number by dividing Gallons Per Hour (GPH) by 60. See Steps 5 and 6. Also, if you would like to see what steps a builder goes through to build a pool, see our guide on "How To Build an In-Ground Pool".Reply
InyoPools Product Specialist Dennis R. Posted: 3/7/2016
wahoo - You may well have a leak around you skimmer. As an older pool shifts in the ground over time, it may cause a crack in your skimmer around the piping. Installing a new motor and pump will not fix this problem if that is what you are suggesting, but it sounds like you are due for a new pump. The energy usage for your pool is the same with 110V or 220V.Reply
Wai Kane Posted: 3/6/2016
Thank you for posting how to calculate the amounts of gallons for a pool.I'm trying to understand how to build a pool, not that I will build one, but just so I have some education on building one when I hire someone.
My question is how do you get the last calculating factor to figure out the amount of gallons?
LxWxDx? = GPH
Also, what does GFM mean?
Thank you once again for your educating me.
Reply
wahoo Posted: 3/5/2016
20 year old motor,50 year old brass pump.110 volt,1 1/2 pipe,hayward DE filter.
Might have leak in skimmer. When I install kreepy K hose and plate, It creates a air bubble under plate,even though it is under water.
Can i install just a new motor and pump?
Does it make sense to go to 22o volts?
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InyoPools Product Specialist Dennis R. Posted: 3/4/2016
ekh443 - A 1 1/2 HP VS pump should be adequate for your size pool if you don't have a lot of extra features.Reply
ekh443 Posted: 3/2/2016
Hello, I just bought a home with a 18,500 gallon pool. It currently runs a Hayward Super II, 2HP single speed pump. I want to switch it out to a VS pump. Do I really need a 2HP?Reply
InyoPools Product Specialist Dennis R. Posted: 3/1/2016
faceache - Your pump is the right size for your system. Your suction cleaner should work at around 2400 RPM and the Spa should run well at full RPM, 3450. It sounds like you have a low water flow problem. See our guide on "How to Correct Low Water Pressure in Your Pool System". A clogged impeller is a common problem.Reply