Giving pool pump a break in winter may cost you later

Apr 07, 2023

Question: Is it OK to turn my pump off in the winter and put a floater with chlorine tablets in the pool? The pool is not heated. We did this back in Maryland.

Related question: A friend has suggested that pool-pump usage could be reduced significantly during the winter. Why bother running the pool pump at all? I have a 16-by-32 screened pool, and I only run the pump a few hours a month in the winter. I usually do this to run the vacuum/cleaner. I also maintain chlorine tabs in a floating container, but sometimes I am lax about that. There is no algae in my pool, and the best I can tell, no harm is done.

There is some pitting beginning to form in my marcite shell, but I am told that this is normal for 10-year marcite without asbestos.

My opinion is that pool stores/companies recommend running the pump in the winter so they can sell more chemicals. This is analogous to the way oil-change establishments recommend that you change your car oil every 1,500 miles when the auto manufacturer states that every 3,000 miles is fine. It's also safe for pool stores to recommend that customers run pumps in the winter.

I would love to know the necessity of running the pump daily during the winter, but I’ve never heard a good explanation, and I’ve noticed no bad effects. Perhaps I am missing something? I really don't want to harm my pool in order to save a few bucks a month in the winter.

Answer: Winterization procedures will vary depending on your region of the country. Because we live in a subtropical climate, turning off the pool pump and using only a chlorine-tablet floater is not a good idea. Though we do have some cold snaps, most of our winter weather is mild to very warm.

The pump is essentially the heart of the swimming pool's circulation system. It pulls water from the pool through the skimmer and main drain(s), pushes it through the filter and returns it to the pool through the main returns. The cleaning/filtration system cannot operate without the pump running. One very important rule to remember: Just because pool water is clear doesn't mean it is sanitary or in proper chemical balance.

Depending on the size of your pool, we still recommend the pump run 8-10 hours per day during the hottest summer months and at least 6 hours per day during the winter months. The daily cycle can be divided into multiple cycles, but each cycle should be no shorter than 4 hours, (this being the minimum time for a small pool) for all the water to pass through the filter at least once.

"Without running the pump the necessary amount of time, the chemicals can't be evenly distributed in the water, and bacteria could grow," warns Steve Bludsworth, owner of All Pool Service and Supply in Orlando. The concentrated chlorine from the floating chlorinator can damage the pool's surface if the water is not properly circulated, adds Bludsworth. It is also bad for the pump motor not to run. Running the motor heats it up and evaporates moisture/humidity that is harmful to the motor.

Pitting or etching appears as pits in plaster or gunite surfaces. It is quite normal for etching/pitting to be visible in a 10-year-old surface. Etching will normally occur in plaster pools, where proper water balance has not been maintained over a period of time.

Low pH, low total alkalinity, low calcium hardness or any combinations of these important water parameters can literally eat away a plaster finish. To prevent this, it is important to maintain proper water balance. Etching can only be repaired by replastering the surface with a new interior finish material.

One final thought: Running the pump does not cause the pool to use any additional chemicals, so this is not a sales tactic by licensed, trained and insured pool professionals.

Paul Roth of Roll-A-Way Protective Pool Fence in Orlando is a member of the Florida Swimming Pool Association, Central Florida Chapter, an industry trade group. Send questions to: In the Swim, Orlando Sentinel, MP-240, 633 N. Orange Ave., Orlando, FL 32801 or e-mail [email protected]. For a list of FSPA-member companies, call 1-800-416-6774.

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