Cold Weather questions for SWG

[DrivenPT]

Hi everyone,

I am going into my first central texas winter with our pool and have a few questions regarding dealing with the occasional cold snaps that come our way.

Number one with the SWG. I am currently set to run 18 hours a day at 30% on our undersized pentair IC20. With the lower temps we’ve had recently I thought we’d be potentially needing to add LC but it seems that we are still overproducing since my FC was at 13 tonight. I guess I should further reduce my SWG percentage to reflect the lower demand? With all the leaves and junk blowing in constantly I am surprised it’s not needed?

Second question is with regards to runtime. Is it better to continue to keep the pump running when temperatures begin to flirt with freezing?

At what sustained temperature should I consider shutting off everything to prevent freeze damage? Or is it not likely to be an issue as long as the power is still on and the water is moving?

Thanks!

 

[jmastron]

In the winter, short days, low sun angle, shade, and lower water temperatures reduce chlorine use dramatically -- in my case by about 90% (when I was using liquid chlorine it took about a gallon every 2 days in the peak of the summer, and a gallon a month in the winter). So it's definitely normal to need a lot less runtime.

SWCGs will stop producing at a certain threshold (my Calimar unit displays "COLD" and doesn't produce at what it measures as 50 degF). Mine does seem to get a bit less efficient in the low 50s, so I sometimes find I need to up the runtime a bit when it starts generating again, then lower when the water temps get to the 60s before ramping up again for the summer. I don't turn it off; I just let it decide whether it wants to generate.

Freeze handling is more location dependent -- where I am the lowest water temps I see are ~42 degF. Nighttime lows can get below freezing here, into the high and sometimes mid 20s, but never for very long -- ironically it can only get that cold when the skies are clear (otherwise the clouds limit radiation), so when the sun comes out it warms above freezing quickly. It's not cold enough long enough to freeze up a 2" pipe solid until it bursts, so I don't take any special precautions even on the coldest nights. For reference, the city water supply pipes come out of the ground and into the side of even new houses here, which was a shock growing up in New England where every single one would have burst

Your general climate may be similar, but I understand many parts of TX can get real sustained freezes, so you might need to take note when it's going to be that cold for more than a few hours. Generally, you want to run the pump (not shut it off) because circulating the (likely well over freezing) water will prevent the pipes from freezing. My IntelliFlo pump has automatic freeze protection that runs below some temperature; I have no idea if that kicks in ever because the pool is far from the house and I'm not out that early! I know there were threads from past TX freezes when power went out, you may want to search for those.

 

[mknauss]

Preparing Pool for Cooler Months - Further Reading

www.troublefreepool.com