new pump recommendations

We have an 18,000 gallon above ground pool with a sand filter and an ic40 Intellichlor SWG. Our 2 spd pump died at the end of last summer. We only ever used it on high speed because the low speed didn’t generate enough flow to run our Intellichlor SWG. I need suggestions for a replacement pump that will be energy efficient AND produce enough flow to run our Intellichlor properly.

We’d be glad to assist you. Do you run your pump on 115v or 230v?

It is 115v

A variable speed pump would be the way to go. Unfortunately, we don’t currently have many options for a 115v variable speed pump. Hayward has model SP26115VSP but it’s only a .85HP pump. This would be a little undersized. If you can have 230v supplied to the, you’ll have more options.

The 230v variable speed pump that we’d recommend is the PureLine model PL2605. That is a 1.65HP pump.

I’ve been told that our chlorinator needs to have a minimum flow of 25 gpm. Is there a 2 speed pump that will generate at least 25 gpm on low speed?

We don’t really want to get into changing the electricity supplied to our pump, so it looks like a variable speed pump is not going to work for us.

We’d recommend the Pentair Whisperflo model WFDS-24. This is a 1HP 2-speed 115v pump. This pump will provide 25gpm on the lower speed. This assumes that the equipment is next to the pool and not a far distance away.

I’ll check out the Pentair. What about the Hayward PowerFlo Matrix model SP15932S? I’ve been leaning toward it.

How can I tell which pumps will provide at least 25gpm on low speed?

I’m checking with Hayward to see if I can get the low-speed power curve or if they can confirm it will push 25 gpm on low-speed. I’ll reply back as soon as I get a response.

The Hayward rep said there wasn’t a power curve for the low speed of the SP15932S. He said that the pump, on low-speed, would likely produce 30%-40% of the full speed flow. If the feet of head is less than 20’, the full speed will produce 91 gpm. This means the range would presumably be 27-36 gpm on low-speed.

Thanks so much for your input! Is there something I should look for when looking at pump specs that would give me an idea of the pump’s gpm?

The feet of head in our plumbing configuration is definitely under 20’.

Most pumps will have a flow chart or power curve. You can figure out the high-speed gpm and then calculate 30%-40% of that number to get the low-speed gpm.

Check out our article titled “How to Read a Pool Pump Curve”.