I’ve researched pump sizing and was doing ok until I encountered head loss and feet per head. I have a 36,000 gallon in ground 20x40 pool with one skimmer and one main drain. There is a 24” fast sand filter which has a 75 gallon flow. The current pump was 3/4 HP, a Hayward Super pump. The pump is probably 15 years old and lately, it’s. It self priming, it’s always been slow to prime and we often have to pour water into the basket. My pressure gauge reads ‘0’ now. The pump overheated a few times recently. I wonder if the pump was ever sized to the pool. Our pipes are 1-1/5”. They are approximately 293’ long. Any suggestions would be appreciated. I’m thinking of going up to 1HP or 1-1/2 HP but I’m definitely no expert. Thanks so much.
Pump replacement advice needed
- Thread starter JoAnne52
- Start date
I had a 3/4 hp single speed and my pool is 1/3 the volume yours is so I'd say your pump is significantly undersized. I went to a 1 1/2 VS and run it 9 hr/day at 1400 with great results. You might be ok but I'm thinking a 3hp VS would be far more suitable.
Others will chime in I'm sure but that's my 2c
Others will chime in I'm sure but that's my 2c
Oly
Gold Supporter
Define how you will use the pump, this will help determine how much hp you may need.
Skimming, pool cleaner, water features, pool heater, salt water FC generator, spa?
I decided on the Pentair SupeFlo 1.5 VS but I only use the pump for skimming and chemical mixing. I never run it at full speed.
A VS pump gives you many motor rpm and flow rate options and they are very quiet.
They cost more up front but can save you in energy costs in the long run.
Skimming, pool cleaner, water features, pool heater, salt water FC generator, spa?
I decided on the Pentair SupeFlo 1.5 VS but I only use the pump for skimming and chemical mixing. I never run it at full speed.
A VS pump gives you many motor rpm and flow rate options and they are very quiet.
They cost more up front but can save you in energy costs in the long run.
Our pool is pretty basic. A skimmer, main drain, two returns. No heater but thinking about finding an automatic cleaner. A post for another day. I don’t know much about variable speed motors but wonder if HP is determined the same way. If my calculations come up with a 1.5 HP for a single speed, is it still 1.5 HP for variable? And VS motors require 220 lines? I guess even a 2 speed is a step in the right direction.
The Hayward super pump has been very reliable and long lasting. I don’t know anything about other brands. Any ideas?
Thanks so much for responding and so quickly. It’s hot and I need to deal with this quickly. JoAnne
Oly
Gold Supporter
Thanks, Jeff. I appreciate your reply. I’ve thought it was sluggish but didn’t know why. I believe it’s undersized but keep reading I don’t want too powerful a pump when the gpm flow is restricted by the 1-1/2” return lines
JoAnne
My lines are 1 1/4 under the slab and 1 1/2 above. Since your considering a VS I'd just add a flow meter then just dial your pump for the volume you want based on run hours for the SWG and keeping the pool filtered. I get 2-4psi at the filter so not much risk of excess pressure.
Pushing more volume through a smaller than ideal pipe will just make it flow faster.
Sorry I didn't read all the other posts before responding. A 1.5 hp VS is based on full power. Dialling it back reduces that of course but if your getting the flow you need then it's just saving you electricity and lasting longer by running at a lower speed. That's the beauty of the VS
Pushing more volume through a smaller than ideal pipe will just make it flow faster.
Sorry I didn't read all the other posts before responding. A 1.5 hp VS is based on full power. Dialling it back reduces that of course but if your getting the flow you need then it's just saving you electricity and lasting longer by running at a lower speed. That's the beauty of the VS
Oly
Gold Supporter
I think we are talking about the returns. As long as the size difference is a step or 2 I can't see the pressure rising to the point of concern. 1 1/2 pvc is awfully robust.
Oly
Gold Supporter
Yes the high pressure concern is primarily between the pump and the filter itself.
Thanks. We’ve always had low pressure. I’m still deciding between 1 and 1-1/2 HP.
Is Pentair rated as high as Hayward. Hayward has a two speed pump which is high/low. Our current Hayward has lasted many years. It’s also less expensive than the Pentair. I like the timer on the Pentair.
Oly
Gold Supporter
Is your current pump wired for 220?
A 2 speed pump will cost less but you will have to manually change the speeds.
A 2 speed pump will cost less but you will have to manually change the speeds.
It is wired for 220. Inyo pools said two speeds are b in phased out and it will be hard to get replacement parts. They are also encouraging the purchase of Pureline pumps about which I know nothing. I wondered if it was advantageous to Inyo. They seem less expensive.
I bought one of their private label LEDs and they replaced it in a blink when it arrived with a rattle. They also seem knowledgeable and open to discuss products so I'd ask who makes their pumps.