You walk into the backyard after a long weekend away, or a heavy North Carolina storm and your heart sinks. The pool that was crystal clear a few days ago is now cloudy, dull, or worse… bright green.

Take a breath. This happens more often than you think, and it doesn’t mean your pool is ruined.

Cloudy or algae-filled water is one of the most common problems pool owners face, especially after heavy rain, extreme heat, or time away.

The good news? With the right approach, most pools can be cleared up quickly. Here’s a straightforward guide to help you go from green to clean without the guesswork.

Step 1: Figure Out What You’re Dealing With

Before grabbing chemicals or adjusting equipment, take a good look at the water.

Cloudy water usually appears milky or hazy but not distinctly green. This often points to filtration issues, unbalanced chemistry, or fine debris stirred up by storms.

Green water is almost always algae. Algae thrives when chlorine levels drop, circulation slows, and warm weather combines with rain and organic debris.

Knowing the difference saves time and helps you fix the problem instead of chasing it.

Step 2: Let the Filter Do Its Job (and Then Some)

After storms or a few days of neglect, your filter becomes your best friend.

Make sure the pump is running properly

Check pressure and clean or backwash the filter if needed

Run the filter continuously — 24/7 if possible — until the water starts clearing

You’d be surprised how many cloudy pools clear up just by improving circulation. This step matters more than most people realize.

Step 3: Test the Water. Every Time

Adding chemicals without testing is one of the fastest ways to make things worse.

At a minimum, test for:

Free chlorine

pH

Total alkalinity

Calcium hardness

Rain and heat can throw water chemistry out of balance quickly. Low chlorine invites algae. High pH makes chlorine less effective, even if there’s plenty of it in the pool. If the results don’t make sense or you’re unsure what to adjust, professional water testing can save you time, money, and frustration.

Step 4: Shock the Pool (The Right Way)

If algae is present, or chlorine is near zero, it’s time to shock.

Use a chlorine shock designed specifically for algae

Add it in the evening so sunlight doesn’t burn it off too quickly

Brush the walls and floor afterward to loosen algae and expose it to the sanitizer

Keep the filter running continuously and wait to swim until chlorine levels return to a safe range.

Step 5: Brush, Vacuum, Repeat

Algae loves to cling to surfaces, especially steps, corners, and tile lines.

Brush the entire pool daily until it clears

Vacuum debris and dead algae, preferably to waste

Empty skimmer and pump baskets often

This hands-on work is often what makes the difference between a pool that clears in a few days and one that stays cloudy for weeks.

Step 6: Clear Up the Cloudiness

Even after algae is dead, the water may still look dull or hazy. That’s normal.

Cloudiness usually comes from tiny particles floating in the water. Good filtration will handle most of it, but a clarifier or flocculant can help speed things along if needed. This is where patience pays off. Keep filtering, keep testing, and avoid piling on unnecessary chemicals.

Step 7: Keep It From Coming Back

Once your pool is clear again, a few simple habits can help prevent future problems:

Maintain consistent chlorine levels, especially during hot weather

Run your filter long enough each day for your pool’s size

Remove debris promptly after storms

Schedule regular water testing and service when needed

A little proactive care goes a long way.

When It’s Time to Call a Professional

If your pool stays green despite shocking, won’t clear after several days of filtration, or chemical adjustments feel overwhelming, it may be time to bring in the experts.

At Rising Sun Pools, we’ve been helping Triangle-area pool owners solve problems like this since 1972. With over 50 years of experience, award-winning service, and a deep understanding of North Carolina’s climate, we’ve truly seen it all, from minor cloudiness to full-blown algae takeovers.

Whether you need professional water testing, routine service, or help getting your pool back on track after a storm or vacation, our locally owned, family-operated team is here to help. Contact us today!