How often should you close your pool for winter?

Why bother

Closing it right prevents freeze damage. Standard upkeep. Dull and cheap, and a lot less dull than whatever it's quietly preventing.

What the job involves

1. Get the water right first. Balance the chemistry and shock it a few days ahead, then skim, brush, and vacuum so it goes under the cover clean instead of turning into a green pond by spring.
2. Lower the water below the skimmer and returns. Roughly 6 to 12 inches below the tile for a mesh safety cover, a few inches for a solid one, and never more than about 18 inches down.
3. Drain every bit of water out of the pump, filter, heater, and chlorinator, then blow the plumbing lines clear with an air compressor or shop vac and plug them. In hard-freeze country, add non-toxic pool antifreeze. This is the step that stops the cracks, so it's the one not to rush.
4. Pull the baskets, ladders, and diving board and store them. Add a winterizing chemical kit and an air pillow, then fit the cover and tie it down properly.

Do it yourself, or pay someone?

Yourself, if you own or can rent an air compressor or shop vac and don't mind blowing out the lines, which is the step that actually matters. Otherwise hire it: closing runs about $250 on average, $150 to $200 above-ground and $200 to $400 inground, with pros around $75 to $100 an hour.

What skipping it costs

$1,500 to $4,500 is the usual bill for water left sitting in the pipes when it freezes. Water expands about a tenth when it turns to ice, and it cracks whatever's holding it: the pump, the filter, the heater, the lines. The low end is a single cracked pump or filter; the high end is a replacement heater. A single hard freeze can take out a whole equipment pad in one night, and a freeze that splits the underground lines means digging up the deck, which runs well past this. Blowing the lines clear costs an afternoon and a borrowed compressor.

Signs it's overdue

• Nighttime lows starting to dip toward freezing while there's still water sitting in the pump, filter, and lines. That water is what cracks.
• The water's fallen below about 60 to 65F and still dropping. That's the window to close, before a hard freeze and well before nights fall under about 30F.
• Last winter you skipped it or rushed it and spring brought leaks, low water, a pump that wouldn't prime, or cracked equipment. That's the lines never getting fully cleared.

When to start thinking about it

Give yourself about 7 days' notice. That's when Grumpty starts grumbling, so it doesn't land on you the day it's due. Mark it done and Grumpty sets the next one, every 12 months, so you can go back to forgetting it exists.

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