Seasonal Checklist

Winterizing & Opening Your Pool in Reno & Sparks

Why winterizing actually matters here

Unlike a mild-winter market, a hard freeze in Reno is a real, recurring event, not an occasional fluke. Water left standing in exposed plumbing, a pump housing, a filter tank, or a heater's heat exchanger expands as it freezes and can crack fittings, housings, and heat exchangers outright — one of the more expensive mistakes a pool owner can make, and one that's entirely avoidable with proper prep. For a sense of how seriously the ground here treats freeze depth: Washoe County's own construction design standards specify a 24-inch frost line for underground work generally — a useful reminder that any pool plumbing running above that depth, or exposed above ground at the equipment pad, genuinely needs real freeze protection, not just a light drain-down. Reno's elevation (roughly 4,500 feet) and dry high-desert air also mean overnight temperature swings can be sharper than a daytime high might suggest — a mild-feeling fall afternoon doesn't rule out a hard freeze overnight once the season turns.

Closing (winterizing) checklist

1. 1. Deep clean and balance the water first. Vacuum, brush, and skim thoroughly, then test and balance pH, alkalinity, calcium hardness, and sanitizer levels before closing. Water that sits unbalanced all winter is more likely to stain the surface, scale, or turn green by spring — see our resurfacing page for what long-term chemical imbalance can eventually do to a plaster surface.
2. 2. Add a winterizing chemical kit or algaecide dose. A dedicated winter-closing chemical treatment (often a combination of algaecide and stain/scale preventer) is standard practice for a pool that's going to sit mostly undisturbed for months, especially under a cover where sunlight-driven chlorine breakdown isn't a factor but algae growth still can be.
3. 3. Lower the water level if you're doing a full winterization. Many Reno pool owners lower the water below the skimmer (and sometimes below the returns, depending on the closing method) so freezing water inside the skimmer or return lines doesn't have anywhere to expand into fittings. Some closing methods keep the water level normal and instead rely entirely on plugs and antifreeze in the lines — ask your contractor which approach they use and why, since both exist and reasonable pros differ on it.
4. 4. Blow out the lines. Using a shop vac or small compressor to clear water out of the plumbing lines running to and from the pool is the step that actually prevents frozen, cracked pipes — don't skip it because the pool "looks" empty enough. This is also, per the FAQ below, the single step most likely to get rushed or skipped by an inexperienced DIY attempt.
5. 5. Add pool-rated antifreeze to the lines (not automotive antifreeze) after blowing them out, per your specific plumbing configuration. Plugs or "Gizzmos" (expansion plugs designed to compress before a fitting cracks) often go in at the skimmer and return lines at the same step.
6. 6. Protect or store equipment. Drain the pump, filter, and heater of standing water per manufacturer instructions, and disconnect and store anything that can be safely removed for the season. Equipment left connected needs its own freeze protection if it can't be fully drained — some owners wrap exposed above-ground plumbing and equipment housings with insulation as extra protection during a Reno winter.
7. 7. Remove or protect a salt cell, if you have one. Salt chlorine generator cells are a component standard closing steps don't always cover — check your system's specific manufacturer guidance.
8. 8. Cover the pool. A proper winter cover keeps debris out over the off-season and reduces algae growth from sunlight exposure — a mesh cover and a solid cover have different tradeoffs (mesh drains rain/snowmelt through but lets some fine debris and light in; solid covers block light better but need a cover pump to remove standing water on top).

Opening (spring) checklist

1. 1. Clear and remove the cover carefully, cleaning off standing water and debris before pulling it so nothing dumps into the pool.
2. 2. Restore the water level back up to normal operating height.
3. 3. Reconnect and reinstall equipment — pump, filter, heater — that was drained or removed for winter, and remove any winter plugs from the lines.
4. 4. Reinstall the salt cell, if one was removed for winter, before running the system.
5. 5. Run the pump and filter to circulate, typically for an extended stretch, before judging water clarity — cloudy or slightly green water right after opening is normal at first and usually clears with a day or two of filtration and a shock treatment.
6. 6. Test and rebalance the water, then shock the pool as needed to clear out whatever built up over winter before swimming.
7. 7. Inspect everything before you fully rely on it. Run the heater, check for leaks around fittings that were disturbed during closing/opening, and listen for anything that sounds different than it did last season — small problems are cheaper to catch at opening than mid-summer.

Mesh vs. solid covers

Both cover types are used around Reno/Sparks, and each has real tradeoffs worth weighing rather than defaulting to whichever your pool already came with. A mesh cover lets rain and snowmelt drain through rather than pooling on top, which means less weight sitting on the cover itself and no cover pump to manage — but fine dirt and some light still get through, which is part of why a good pre-closing chemical treatment matters. A solid cover blocks light and debris more completely (helpful for algae prevention over a long closure), but needs a cover pump to remove rain and snowmelt that collects on top, since a heavy, waterlogged solid cover is both harder to manage and a safety hazard if it sags.

Protecting decking and surrounding hardscape over winter

Winterizing usually focuses on the pool and its equipment, but a hard freeze-thaw cycle is also tough on the concrete decking, coping, and any nearby retaining or block walls around the pool — surfaces that expand and contract with repeated freezing the same way exposed plumbing does. Clearing standing water off decking before a freeze, and not leaving heavy planters or furniture sitting in one spot on pavers all winter, are simple steps that reduce cracking risk on the hardscape itself, separate from the pool and its equipment.

If you think a freeze already caught you off guard

If an early or unexpected hard freeze hits before you've closed the pool, don't just assume the worst and panic — but don't ignore it either. Check the equipment pad for any visible cracking, listen for anything unusual when you next run the pump, and watch the water level over the following days for a drop beyond normal evaporation (see our leak help page for how to tell). Catching freeze damage early, before you've run the system repeatedly on a cracked component, generally means a smaller repair bill than discovering it mid-summer after months of undetected damage.

When it's worth calling a pro instead of DIY-ing it

Winterizing and opening are DIY-able for a lot of pool owners, but a few situations are worth getting an independent contractor's help with:

• Suspected freeze damage. A crack, a leak that shows up right at opening, or an equipment pad with visible damage after a hard winter — see our leak help page if water level is dropping after reopening.
• Equipment won't start after storage. A pump or heater that sat all winter and won't come back on cleanly is worth a real diagnosis — see pump & filter repair or heater repair.
• You've never blown out lines before. Getting this step wrong is exactly what causes the expensive freeze damage this whole page is trying to help you avoid — a first-time DIY attempt on an expensive pool is a reasonable place to get help instead.
• Spa/hot tub systems combined with your pool equipment. Combo systems add complexity — see spa & hot tub repair if something's off after a seasonal transition.
• You're closing up a pool you just bought and don't know its history. An unfamiliar system's plumbing layout and equipment condition are worth a professional look the first time around, even if you plan to DIY future seasons yourself.

A rough seasonal timeline for Reno/Sparks pool owners

Every pool and every season is a little different, and you should always weigh the actual forecast over a calendar rule of thumb — but as a general planning reference based on the frost-date data above:

• Late summer / early fall: last full month of normal swim-season use; a good time to schedule any repair or resurfacing work you've been putting off before equipment sits idle for winter.
• Early-to-mid October: frost risk starts building — this is the window to plan your closing date around, watching the extended forecast rather than a fixed date.
• Late October through winter: pool closed, equipment protected or removed, cover on. This is also, per the resurfacing section above, not the season most contractors want to take on a resurfacing project, since curing plaster needs to stay above freezing.
• Mid-to-late April: median last frost date passes — most owners start planning their opening from here, again watching the forecast rather than committing to a fixed date on the calendar.
• Late spring: full reopening, chemical rebalancing, and equipment inspection before the swim season really gets going.

Before you hire

Reno Pool Repair Pro doesn't perform winterizing, opening, or any repair work ourselves — we match you with an independent, NSCB-licensed contractor for that. Verify any contractor's A-10/A-10e license at https://app.nvcontractorsboard.com before hiring — see our full verification page, or head to the repair cost hub for whatever specific issue brought you here.

Frequently Asked Questions