Swimming Pool Blog
by Rob Cox December 03, 2013
Salt Chlorinators during Winter
Salt Chlorinators are a marvelous invention, add salt to the pool, turn on the salt cell controller and make your own chlorine! As an added benefit, the water is silky smooth, leaving skin feeling refreshed, not dry, and the production of chloramines is significantly reduced.
But, for pool owners in the sunbelt - those who operate their pool all year around, there is a hidden complication. This may have not been made clear to them when they purchased their salt water chlorinator.
Salt cells don't work well during winter
Specifically, at water temperatures below 60 degrees, conductivity of the salt is severely hampered. This causes the salt cell to work much harder to produce chlorine, which can shorten the lifespan of your salt cell.
Salt Cell Self Preservation
Many salt chlorinators have a temperature sensor, which automatically reduces chlorine production when temperatures drop below 60 degrees, and stops production altogether when water temps reach 50 degrees. Other units have a Winter Mode, which is manually activated, to reduce production to around 20%. These are designed to protect the salt cell, to keep it from working too hard, which again, will shorten the lifespan of the expensive-to-replace salt cell.
The good news is, that pools at such low temperatures don't need much chlorine anyway, algae and bacteria have a hard time growing when the water is cold. So - a 20% production should be sufficient to maintain water clarity.
Alternative Winter Chlorination
My recommendation would be to shut off the salt cell completely when your water temperatures reach 60 degrees, and switch over to using chlorine tablets, in a chlorinator or in a chlorine floater. Another option would be to treat the pool every few weeks with liquid chlorine, or bleach.
You can use regular Clorox bleach, adding 1 gallon for each 20,000 gallons, to raise the chlorine level to 1.0 ppm. Remember to check and balance your pH level and maintain at least a 20 ppm residual of cyanuric acid (stabilizer) to protect the chlorine level from winter sunlight.