If you've walked outside to find your once-crystal-clear pool looking green, you're not alone. It's one of the most common service calls we receive from homeowners in Weston, especially during South Florida's rainy season. A green pool doesn't necessarily mean your pool is beyond saving—but it does mean something is out of balance. Whether the water has a slight green tint or resembles pea soup, identifying the cause early can save you time, money, and frustration.

Here's what every Weston homeowner should know about why pools turn green—and how to get them clean again.

The Most Common Cause: Algae Growth

In nearly every case, green pool water is caused by algae.

Algae spores are naturally present in the environment and constantly find their way into pools through wind, rain, leaves, grass clippings, swimmers, and pool equipment

Normally, chlorine kills algae before it becomes visible. But when chlorine levels drop—or the water chemistry becomes unbalanced—algae can multiply rapidly.

Thanks to Weston's warm temperatures and year-round swimming season, algae can begin growing much faster than homeowners expect.

Why Weston Pools Are Especially Prone to Green Water

Unlike many parts of the country, pools in Weston stay open all year.

That means your water is constantly exposed to conditions algae loves.

Heavy Summer Rainfall

From late spring through early fall, Weston experiences frequent afternoon thunderstorms. Heavy rain can dilute chlorine, lower sanitizer levels, introduce organic debris, change water chemistry, and wash fertilizer into the pool After several rainy days, many homeowners discover the water beginning to turn cloudy or green.

High Temperatures Accelerate Algae Growth

Warm water creates the perfect environment for algae. When pool water temperatures remain in the upper 80s for weeks at a time—as they often do in Weston—algae reproduces much more quickly than during cooler months. If chlorine isn't maintained consistently, algae can take hold in just a few days.

Shade Can Make Things Worse

Many Weston neighborhoods feature mature landscaping and tree-lined streets. While shade keeps your backyard comfortable, it can also reduce water circulation and create ideal hiding spots for algae along walls, steps, and corners. Leaves and organic debris from nearby trees also consume chlorine as they decompose.

Other Reasons Your Pool May Be Green

Although algae is the most common culprit, it's not the only possibility.

Low Chlorine

Without enough free chlorine, algae has an opportunity to grow. Common reasons for low chlorine include chlorine drops include heavy rainfall, increased swimmer use, high UV exposure, equipment issues, and salt system problems. Testing chlorine is always one of the first steps in diagnosing a green pool.

Poor Water Circulation

Your pool pump should circulate water long enough each day to properly filter the pool. If your pump isn't running long enough—or isn't working efficiently—dead spots develop where algae can grow. Many homeowners don't realize an aging or improperly programmed pool pump may contribute to recurring algae problems.

Dirty or Clogged Filter

Your filter removes microscopic particles from the water. When it's dirty or overdue for cleaning, algae spores remain in circulation instead of being removed. Whether you have a cartridge, DE, or sand filter, routine maintenance is essential to preventing green water.

Unbalanced Water Chemistry

Even if chlorine levels appear acceptable, other chemical imbalances can reduce its effectiveness. Problems with pH, total alkalinity, and cyanuric acid (stabilizer) can all interfere with chlorine's ability to sanitize your pool. Professional water testing often identifies issues that standard test strips may miss.

How to Turn a Green Pool Blue Again

The exact treatment depends on how severe the algae bloom has become, but the general process is usually:

1. Test the Water

Determine free chlorine, combined chlorine, pH, alkalinity, stabilizer, and calcium hardness. Without accurate testing, adding chemicals becomes guesswork.

2. Brush Every Surface

Algae clings to walls, steps, ladders, tanning ledges, and corners. Brushing loosens algae so chlorine can reach and kill it more effectively.

3. Shock the Pool

A heavy chlorine treatment kills active algae. Depending on the severity of the bloom, more than one treatment may be necessary.

4. Run the Pump Continuously

During cleanup, circulation is critical. Running your filtration system 24 hours a day until the water clears helps remove dead algae and improves chemical distribution.

5. Clean the Filter

Dead algae quickly clogs filters. Cleaning or backwashing during the cleanup process helps maintain good circulation and speeds recovery.

When DIY Isn't Enough

Some green pools recover within a day or two. Others require professional treatment.

You should consider calling a pool professional if:

• The water is dark green
• You can't see the bottom
• The pool remains green after shocking
• Algae keeps returning
• Your equipment isn't operating correctly
• Water chemistry won't stabilize

Trying to fix a severe algae bloom without addressing the underlying problem often leads to repeated outbreaks.

How Weston Homeowners Can Prevent Green Pools

Preventing algae is much easier—and less expensive—than removing it.

A consistent maintenance routine should include: weekly water testing, proper chlorine levels, regular brushing, skimming debris, cleaning the filter, maintaining proper circulation, and checking equipment performance after major storms

Professional weekly pool service helps identify small issues before they become expensive cleanups.