Will A Two Speed Pump Work For Me…Help Please

[Mlamb]

Thanks to TFP for the education they have provided me. After resurfacing the pool and spa in 5/17 and using the TFP method for those 3 years, my pool has consistently been clear and sparkling.

Since the pool was built 23 years ago, I’ve had a 1 ½ HP (SF 1.10) single speed pump that I’ve replaced several times. The pump is making a all too familiar noise, so I think it’s on the way out. I would like to replace it with a two-speed pump and was looking at a Pentair WhisperFlo as the replacement since the plumbing looks like it will mate up exactly. The fountain and spillway are on for the eight hours I run the pump (wife likes it that way, so I deal with the PH). So here are my questions:
1. Are there any compatibility issues with this Pentair pump and Aqualogic automation?
2. I want to be able to run on low speed and still have the fountain and spillway on and have good skimming. What HP pump and impeller should I get to provide as close to the flow I presently have if that’s even possible. The pool supply and return are 2” lines and the spa supply and return and fountain are 1 ½” lines. The skimmer is 30’, main drain 35’ and 2 of the returns are 35’ and one 50’ from the equipment pad. The pressure on the filter gauge, when clean is 20 psi.
3. I’m open to other brands of pumps even if that requires some plumbing modifications if that would get me to the flow needed.

 

[ajw22]

1. Are there any compatibility issues with this Pentair pump and Aqualogic automation?

If you want to control the speeds on your Aqualogic you need two high voltage relays available to select high speed or low speed.

2. I want to be able to run on low speed and still have the fountain and spillway on and have good skimming. What HP pump and impeller should I get to provide as close to the flow I presently have if that’s even possible. The pool supply and return are 2” lines and the spa supply and return and fountain are 1 ½” lines. The skimmer is 30’, main drain 35’ and 2 of the returns are 35’ and one 50’ from the equipment pad. The pressure on the filter gauge, when clean is 20 psi.

If you want the flow that your current 1 1/2 HP pump gives you then youw ant 1 1/2 HP. So why not just get another 1 1/2 HP pump since that is the flow you want.

Any lower speed and HP will give you a lower flow.

3. I’m open to other brands of pumps even if that requires some plumbing modifications if that would get me to the flow needed.

They are all the same.

 

[Mlamb]

Thanks for the reply. I was looking to reduce operating cost and noise by running on the lower speed. If I went to a larger full rated horse power pump would that increase the flow to accomplish what I want to do.

 

[ajw22]

Thanks for the reply. I was looking to reduce operating cost and noise by running on the lower speed. If I went to a larger full rated horse power pump would that increase the flow to accomplish what I want to do.

There is no way of knowing what flow you will have and if you will be satisfied. You pay your money and take your chances.

If you spring for a VS pump then you can adjust it to whatever RPM/HP you like.

 

[bmoreswim]

And it's often noted that going with a smaller VSP, say Hayward's 1.85 HP, is not much more cost effective than just getting the full bore 3 HP, more popular version. There is an up-front cost difference though of a few hundred dollars. I went with the smaller one because I never need 3 HP and it cost less up front. Ongoing costs are what they are. But man is this thing quiet at lower RPM's compared to my previous two-speed 2 HP.