why your pool chemistry acts up in the rainy season-and how to prevent it

Why Your Pool Chemistry Acts Up in the Rainy Season—and How to Prevent It

South Florida's rainy season brings much-needed relief from the heat, but it can wreak havoc on your pool water. Between frequent downpours, high humidity, and stormy winds, your pool’s chemistry can shift quickly—often overnight. If your crystal-clear pool turns cloudy or green after a storm, you’re not alone.

Here’s why your pool chemistry changes so dramatically during the rainy season—and what you can do to keep your water clean, balanced, and swim-ready all summer long.

What Rain Does to Your Pool

Rain may seem harmless, but when it comes to your pool, it introduces a host of issues:

• Alters pH levels: Rainwater is slightly acidic and can lower your pool’s pH, making the water more corrosive.
• Introduces contaminants: Dirt, pollen, leaves, and debris from wind and runoff can throw off your chemical balance.
• Dilutes sanitizers: Heavy rain dilutes chlorine and other sanitizing chemicals, making your pool vulnerable to bacteria and algae.
• Can temporarily raise water levels: Some pools may appear full after a storm, but in most Florida pools, the water level naturally drops 2–3 inches within a day due to drainage and evaporation.

Common Problems You’ll See

After a storm or several rainy days, you might notice:

• Cloudy or green water
• Algae blooms
• Low chlorine levels despite recent treatment
• Rust stains or etching due to low pH
• Skimmer baskets overflowing with debris

How to Protect Your Pool During Rainy Season

Stay ahead of the rain with these expert tips to maintain your water balance and prevent costly issues:

1. Test Your Water Frequently

Test your pool water at least 2–3 times per week during rainy periods. Keep an eye on pH, chlorine, alkalinity, and stabilizer levels. Use test strips or a drop test kit for more accuracy.

2. Shock Your Pool After Heavy Rain

Rain dilutes chlorine and adds contaminants. After heavy storms, give your pool a shock treatment to kill off bacteria and prevent algae growth.

3. Keep Skimmers and Filters Clear

Debris builds up fast after storms. Clean your skimmer baskets and check your filter pressure. Backwash or clean your filter cartridges regularly to maintain good flow and filtration.

4. Monitor Salt Levels (For Saltwater Pools)

Rain can lower salt levels and trigger error messages like “Check Cell” or “Low Salt.” Always check your salt system after a rainstorm and clean the cell if needed.

5. Why You Shouldn’t Drain the Pool

In South Florida, most pools are built with proper drainage and naturally lose 2–3 inches of water within a day after heavy rain. This happens due to built-in drainage systems and fast evaporation from our hot, humid weather. Draining your pool manually right after a storm can actually backfire—causing you to end up with less water than needed once natural water loss occurs.

On top of that, draining increases the need for chemical rebalancing, wasting time and money. Unless you're dealing with flooding or overflow into your home, it's best to let your pool adjust on its own within 24 hours.

Need Help Keeping Your Pool Balanced?

Rainy season can make pool maintenance more challenging—but you don’t have to do it alone. At Sparkling Pools Service & Repair, we specialize in keeping South Florida pools clean, clear, and perfectly balanced year-round, no matter the weather.

From weekly service to salt system checkups and algae treatments, we’ve got you covered.

Contact us today to schedule your pool service or get a quote!