Closing your pool for the season isn’t just about lowering the water level and tossing on the cover. In fact, how you close your pool now has a direct impact on what you’ll face when it’s time to open it next spring.

The difference between a clean, clear pool in April and a green, cloudy mess often comes down to how well you prepare your water before closing day. And that prep starts with one simple goal: close clean.

Here’s why it matters and what steps you can take now to protect your pool during the off-season.

If algae is already starting to form when you close your pool, it won’t magically disappear over the winter. Even with cold water and a safety cover in place, algae spores can survive and continue to grow in the right conditions.

That means if your water is unbalanced or untreated, you could open up to green, cloudy water that takes weeks to clear.

What to do:

• Make sure your sanitizer level is in range at closing
• Brush and vacuum thoroughly to remove algae spores and organic matter
• Consider a final dose of an algaecide or a weekly care product, like E-Z POOL®, leading up to closing day

Swimmer waste, sunscreen, body oils, pollen, and other organics don’t vanish when the pool is closed. They settle into the water, breaking down slowly over the winter. When spring arrives, these leftover contaminants can contribute to strong odors, cloudy water, and increased chlorine demand.

What to do:

• Treat your water with a natural enzyme like ENZymePRO® before closing, which helps break down organic waste so it doesn’t sit and cause problems under the cover

Don’t skip this step even if your pool hasn’t been used much in recent weeks.

Fill water, rain, and runoff can introduce metals like copper and iron into your pool. If left untreated, these metals can stain surfaces, discolor water, and increase the likelihood of scale buildup over the winter.

Phosphates—often introduced through plant debris or runoff—act as food for algae, even in colder months.

What to do:

• Use a product that targets both metals and phosphates before closing
• Revive!® START UP/CLEAN UP is an excellent option here—it removes up to 2 ppm of metals and 2000 ppb of phosphates in one application. It also captures debris and organics, settling them for easy vacuuming before closing

Unbalanced water (especially if it’s high in pH, alkalinity, or calcium hardness) can result in scaling and staining while your pool sits dormant. Once those marks set in, they’re much harder to remove.

What to do:

• Test and adjust water chemistry one final time before closing
• Focus on pH (ideal: 7.2–7.6), alkalinity (80–120 ppm), and calcium hardness (200–400 ppm)
• Use stain and scale preventers or an all-in-one closing solution that includes them

Product note:

If you’ve been using E-Z POOL®, you already have stain and scale protection built into your weekly care. Just make sure to dose appropriately before closing.

When you close a pool that’s clean, clear, and properly treated, you set yourself up for:

• Less time and fewer chemicals needed at opening
• Fewer surprises like stains, scaling, or heavy algae blooms
• A quicker return to safe, swim-ready water in the spring

In short, investing in a final cleanup now saves you money and time when the season starts again.

Closing your pool is one of the most important maintenance steps of the year—but it’s also one of the most overlooked. Taking the time to brush, balance, treat, and clear your water before covering it is the best way to protect your investment during the off-season.

So before you pull the cover on, ask yourself: Is my water really ready to be sealed up for the winter?

A clean closing now means a much easier, cleaner, and stress-free start to next season. And your pool will thank you for it.