A proper pool closing is the single biggest thing you can do to protect your equipment through a Colorado winter — and make next season's opening a two-hour job instead of a week-long headache.
A lot of homeowners assume that dropping the water level and pulling on a winter cover is enough to protect their pool. It isn't. A proper closing is a multi-step process that treats the water chemistry, protects plumbing and equipment from freeze damage, clears filters and lines, and installs a cover that will actually hold through a Colorado winter.
Done right, your spring opening is straightforward — remove the cover, balance the water, fire up the equipment, done. Done wrong, you're looking at cracked pipes, damaged pump seals, a green pool that takes weeks to recover, and repair bills that dwarf the cost of a professional closing.
We've seen both outcomes. The difference is almost always whether the closing was done properly in the fall.
We test and balance your water before closing — pH, alkalinity, calcium hardness, and stabilizer — then add a closing chemical kit that includes a long-acting algaecide, stain and scale preventer, and oxidizer. This chemistry keeps the water from going green or developing staining during the months it sits idle. Skipping this step is the most common cause of difficult spring openings.
We lower the water level below the skimmer and return lines — the exact depth depends on your pool type, cover style, and plumbing configuration. This prevents water from sitting in components that will freeze and expand. Getting this wrong — too high or too low — creates problems on both ends.
We use compressed air to blow out all return lines, skimmer lines, and equipment plumbing to clear any remaining water. Plugs are then installed in all returns and the skimmer. Any water left in lines will freeze, expand, and crack — this step is non-negotiable for Colorado winters where temperatures regularly drop well below freezing for weeks at a time.
Filter media is cleaned and the tank is drained. Pump baskets are emptied and lids left loose or removed for winter. Heater drain plugs are pulled and stored inside. Cartridge filters are removed and dried. Any equipment left with standing water in it will suffer freeze damage — we go through every component methodically so nothing is missed.
Ladders, handrails, diving boards, and any deck equipment are removed from the pool and set aside for storage. Plastic and aluminum components become brittle in sustained cold and the freeze-thaw cycle causes cracking and warping when they're left installed. Five minutes of removal prevents unnecessary replacement costs in spring.
We install your safety or winter cover properly — secured, tensioned, and checked around the perimeter. A loose cover lets in debris, allows UV to hit the water, and can collapse into the pool in heavy snow or wind. We also add water bags or anchors as needed depending on your cover type and deck configuration.
Colorado's fall weather is unpredictable. A week of 70-degree days can be followed immediately by a hard freeze with no warning. The right closing window is narrower than it seems — and getting it wrong in either direction causes real problems.
Closing while water is still warm — above 65°F — creates ideal conditions for algae to develop under the cover all winter. You'll open to a green pool in spring regardless of what chemistry you added at closing.
Late September through mid-October for most of the Denver metro. Water temperature drops below 65°F, algae growth slows significantly, and there's still enough time to close before the first serious freeze. Southern suburbs can push slightly later; northern and higher-elevation areas should close earlier.
Waiting until after the first hard freeze means water may have already gotten into equipment and begun to expand. Even if pipes don't visibly crack until spring, the damage is done. Emergency closing slots are also limited — early booking gives you control over the timing.
The most expensive pool repairs we see each spring share a common cause — an improper or missed closing the fall before. These aren't freak accidents; they're predictable outcomes of skipping steps that protect equipment designed to hold water, not ice.
A professional closing from Pyle's runs a fraction of what any one of these repairs costs. It's the most straightforward investment in your pool's longevity you can make each year.
Water expands 9% when it freezes. Any standing water left in return lines, skimmer bodies, or equipment manifolds will crack plastic fittings and PVC pipes — repairs that require excavation in some cases.
Pump housings, impellers, and filter tanks that aren't fully drained crack under freeze pressure. Replacement costs typically run $300–$1,200+ depending on equipment.
Pool heaters are the most expensive piece of equipment to replace. A drain plug left in means water stays in the heat exchanger — which cracks under freeze pressure and requires full replacement.
Improper closing chemistry or a cover that let light in means you open to algae-heavy water that takes chemicals, time, and multiple visits to recover — delaying the start of your swim season.
Closing slots fill up in September. Reach out now to lock in your date — we'll confirm the right timing for your pool and handle everything from chemistry to cover installation.