SWG that works in the cold?

wptpool

Gold Supporter
Sep 2, 2019
21
Westport, MA
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.

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. :)
 
Welcome to the forum!
All SWCG's to my knowledge shut off at ~55F.
But that is not a reason to not get a SWCG. When your pool water is below 60F, you will consume very little FC. With the pool open you should still be testing at least weekly when the water is that cold. It might take a quart or so of liquid chlorine (depending on pool volume) each week to keep your FC in target range. See FC/CYA Levels.
I suggest you read ABC's of Pool Water Chemistry.
 
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Thank you MKnauss! I will read up on the ABC's. With my interest in keeping the pool open as long as possible do you think I should be considering getting one of Autopilots SWCGs over other brands? (If not, I'd likely want to stick to one of the big 3 -- Pentair, Hayward or Jandy -- so that I can be confident it works as well as possible with my other components. (I take it that you favor Pentair?)
 
Yeah, its a limitation of the technology. I've been tempted to try running my SWG when the heater is on just to see if it produces in the winter.. but then again the CL demand is so low in the winter its not worth it. I don't really "close" my pool during the winter. It just kind of goes dormant. The challenge is to start ramping up the FC before the algae critters wake up. Sometimes I miss it and I have an early season SLAM to contend with.
 
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I see all of that language as marketing speak.
In my opinion "down to 1% at 55F" means it wont work at all at any lower. Given the TFP recommended FC/CYA ratio, again, IMO, I dont see the SWG making chlorine for 1 minute out of a 100 as being useful.
 
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I believe you should get whatever SWCG meets your needs.
If you could fill out your signature it would help us provide more targeted feedback.
 
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