Swimming Pool Blog

Sunbelt Pool Winterization

Sunbelt Pool Winterization
by Rob Cox, October 24, 2012
Sunbelt Pool Winterization

frozen poolAsk most sunbelt pool owners about pool winterization, and they look at you kind of funny. For most sunbelters, it's rare that the pool freezes over, like in the picture, because most sunbelt pools are kept circulating, with only occasional dips below 32 degrees.

As the weather turns cool, the average sunbelt pool is used very little, maybe not at all. Even so, the southern pool owner has to continue operating the pool pump, keep the water balanced and clean. There are times - below freezing temps, where the pump must be running to prevent freeze damage.

freeze map

If you'd rather not worry about the pool this winter, and save 4-5 months of pump electricity and chemical expense - you can do a partial pool winterization. For many of those in the white portions of the map, a partial pool closing can be preferable to maintaining an unused pool all year around.


1. Balance your water chemistry

You know - pH, Alkalinity and Calcium Hardness levels. Use a quality test kit and adjust to correct levels. After balancing, shock the pool with either chlorine or non-chlorine based pool shock.

2. Vacuum, Brush and Skim your pool

In that order. Even if your pool cleaner keeps your pool very clean, a good brushing of the pool surfaces, with a good pool brush is important before shutting down for the winter.

3. Lower the water level below the skimmer

If you have a separate main drain, close the skimmers and continue backwashing or draining water to 1-2" below the skimmer opening for a solid cover, or 6-8" for a mesh cover. You can usually "suck the skimmers dry", after the water level has dropped below the opening to the skimmer. Do this by opening the skimmer valve slowly, while it's running full steam on the main drain only. You may be able to hear the skimmer sucking air, just before the air gets sucked into the pump. Just as the air from the skimmer line reaches the pump, close the valve quickly, to resume pumping from the main drain only. Using this method, you will remove most of the water from the skimmer.

4. Cover the Pool

Options for covering the pool include safety pool covers, solid pool covers and leaf nets. Safety pool covers can be either mesh or solid, and are made to fit the exact shape of your pool (plus one foot all around). These covers anchor into the deck for safety, they look great, and can last over 12 years. Solid covers are laminated polypropylene tarps that float on the water, and are held in place with water bags placed around the edge. A small cover pump, attached to a garden hose, is needed to pump off rain water.

Leaf nets are not really meant to be used as a winter cover, but would be better than having none at all. Leaf nets will block some of the sun, but not nearly as much as a solid cover or a safety cover.

Blocking the sun is a big part of what winter pool covers do, in addition to keeping debris and dust out of the pool. This will help to ensure that your unfiltered water will stay fresh and clean. Without a winter cover, most stagnant pools will grow algae when water temps are above 60 degrees.

5. Drain the Equipment

If your pool equipment is below the level of the pool water, draining the equipment is difficult, and different steps would be involved. But, assuming that your pump and filter is at or above water level, you can simply remove the drain plugs on all your pumping, filtering, heating and sanitizing equipment. Move all of your valves, including the backwash valve, to make sure no water is left standing inside or up against a closed valve.
pool antifreeze

What about the underground plumbing lines? For most sunbelt pools, these need not be drained or blown out, as they are for snowbelt pools. For the water to freeze in underground pipes, a freeze of 1-2 weeks duration is usually necessary. If you want to add some insurance, you can pour some pool antifreeze into the skimmer lines, and use a hose to pour some into your return lines. An extra step for skimmers is to plug the lines with winter plugs.

And that's how you can winterize a sunbelt pool. It's everything a northern pool would do, with the exception of blowing out the lines. The benefits to this type of partial winterization for sunbelt pool owners are:

  • Reduce pool maintenance for 4-6 months.
  • Reduce wear and tear on your pool equipment.
  • Reduce electrical and chemical consumption.
  • Increase pool safety, when a safety cover is used.