I'm planning a new 40 x 20 gunite pool with a SWG and VS pump for my home in Massachusetts.
We're interested in opening the pool very early and closing it very late -- opening in April/May and closing in November/December. The idea is to be able to take "polar bear plunges" into it after being in a standalone hot tub. We're aware the water will be freezing and that we'll only want to stay in it for seconds. (At this point, we're thinking the pool won't have a heater initially, but we might add one in the future.)
And then I came across this 2015 post from Autopilot boasting how much better their SWGs work in the cold versus the competition.
autopilot.com
This is where AutoPilot blows the competition out of the water. AutoPilot has the industry’s only patented Automatic Temperature Compensation feature, which automatically adjusts the purifier percentage setting to compensate for changes in water temperature. This feature will adjust the purifier percentage setting, which determines the amount of time the cell is activated, and helps maintain proper chlorine levels throughout the year. As temperatures get colder, the AutoPilot system will not shut off, as other models do. Rather, the output percentage will simply decrease. While most systems shut down around 55- 60°F, AutoPilot will continue to work, automatically reducing its purification level down to 1% at 55°F. Even at these low temperatures, the unit will still introduce a minimal level of chlorine to maintain a residual amount in the pool.
Couple of questions:
1. Is it true that Autopilot has a big advantage over all other SWGs in the cold?
2. Does this part, "AutoPilot will continue to work, automatically reducing its purification level down to 1% at 55°F." mean that even Autopilot will stop being effective below 55 degrees
3. Should I be rethinking keeping a pool open from April/May to November/December in Massachussets? Or rethinking using SWG?
I will be a first time pool owner so setting me straight is appreciated.
We're interested in opening the pool very early and closing it very late -- opening in April/May and closing in November/December. The idea is to be able to take "polar bear plunges" into it after being in a standalone hot tub. We're aware the water will be freezing and that we'll only want to stay in it for seconds. (At this point, we're thinking the pool won't have a heater initially, but we might add one in the future.)
And then I came across this 2015 post from Autopilot boasting how much better their SWGs work in the cold versus the competition.
Do Salt Chlorine Generators Work Well In The Winter? - AutoPilot Website
If you are like many pool owners, you have learned how wonderfully effective salt chlorine generators (SCGs) are at keeping your pool water sparking clean all summer long. But what about after summer has passed—will your salt chlorine generator work as well in the winter months? To understand...

This is where AutoPilot blows the competition out of the water. AutoPilot has the industry’s only patented Automatic Temperature Compensation feature, which automatically adjusts the purifier percentage setting to compensate for changes in water temperature. This feature will adjust the purifier percentage setting, which determines the amount of time the cell is activated, and helps maintain proper chlorine levels throughout the year. As temperatures get colder, the AutoPilot system will not shut off, as other models do. Rather, the output percentage will simply decrease. While most systems shut down around 55- 60°F, AutoPilot will continue to work, automatically reducing its purification level down to 1% at 55°F. Even at these low temperatures, the unit will still introduce a minimal level of chlorine to maintain a residual amount in the pool.
Couple of questions:
1. Is it true that Autopilot has a big advantage over all other SWGs in the cold?
2. Does this part, "AutoPilot will continue to work, automatically reducing its purification level down to 1% at 55°F." mean that even Autopilot will stop being effective below 55 degrees
3. Should I be rethinking keeping a pool open from April/May to November/December in Massachussets? Or rethinking using SWG?
I will be a first time pool owner so setting me straight is appreciated.