Why Is My Pool Cloudy? Getting to the 3 Reasons Your Water is Murky

You walk outside, ready for a swim, but your pool looks cloudy. Ugh! It’s not clear and blue. It looks kind of foggy and weird. Super frustrating, right?

Don't worry, you’re not alone. Many pool owners deal with this. The good news? Cloudy water is your pool’s way of saying, “Hey! Something’s not right. Please check me!”

In this blog, we’ll explain what might be going on in your pool. No confusing stuff, just plain, simple reasons why the water turns cloudy and what they really mean. Let’s get started. 

What Is Actually in the Water Making It Cloudy?

Before we learn why your water is cloudy, let's consider the floating objects instead. 

Cloudy water refers to countless tiny items like dirt and oils floating in your pool. You can not see them all, but they are what makes your water murky. The two main categories of things in cloudy water are: 

1. Non-living particles, like dust, rocks, sunscreen, dead skin, and even minerals such as calcium. 
2. Living organisms, like tiny algae (the stuff that turns pools green) or little bacterial colonies, start to grow.

Gross, right? But now, let’s figure out why this happens. 

What Causes Cloudy Pool Water? Uncovering the 3 Main Reasons

Here are the top 3 big reasons why your pool water gets cloudy:

Reason 1: Chemical Imbalances

This is the most common reason. Your pool has chemicals that help it stay clean, but if they’re not balanced, things go wrong fast.

a) Chlorine Confusion

Chlorine is your pool’s best friend. It kills germs. But there are two types:

• Free Chlorine (FC). This is the good one that works.
• Combined Chlorine (CC). This is the “used-up” chlorine that smells bad and does nothing.

When CC gets high, your water gets cloudy. Pro tip? Keep CC below 0.5 ppm.

b) The pH Problem

Even if your chlorine is good, when your pH is too high (above 7.8), chlorine is weakest. Like really weak. 

To explain, it's as if chlorine makes cleaning your pool, but has high pH like handcuffs to the cleaning action. It just cannot perform its action. 

Added to the already high pH reading of 7.4 to 7.6, chlorine could not do its job. Recommend reading: How to Adjust pH in Pool. 

c) Too Many Minerals (The Water is Full!)

Water can only hold so much stuff. When it gets overloaded with things like calcium or alkalinity, it can’t keep them all dissolved. So they fall out, making the water cloudy.

Experts use a tool called LSI to check this, but you can ask your local pool store to help if you think this is the issue. 

Reason 2: Filtration & Circulation Failures

Your pool also needs a “cleaning machine”, that’s your filter and pump. If those aren't working right, cloudiness sticks around.

a) The Pump Isn’t Running Long Enough

Your pump needs to run for enough hours to clean all the water in your pool. This is called a "turnover." In hot places like Arizona, try running it 8–12 hours every day.

b) Filter is Clogged or Dirty

Imagine using a sponge that’s already full of dirt; it won’t clean anything. That’s your filter if you don’t clean it.

Check your filter’s pressure gauge. If it’s 8–10 PSI higher than normal, it’s time to clean it.

• If you have a sand or D.E. filter, you’ll need to backwash.
• If you have a cartridge filter, rinse or replace the cartridge.

c) Not Using a Robotic Cleaner

A robotic pool cleaner helps a lot! It picks up dirt and leaves before they reach your filter. Think of it like a mini helper that cleans all day. It keeps your water cleaner and makes your filter last longer.

Reason 3: Environmental Overload

Sometimes your pool gets cloudy after something happens outside. Let’s talk about those events.

a) Rainstorms. Rain isn’t just water; it brings dirt, dust, and messes with your pool’s pH.

b) Dust Storms. If you live in a place like Phoenix, you’ve seen those big dust clouds, called haboobs. They dump tons of tiny dust into your pool, which makes it cloudy fast.

c) Pool Parties. More people = more sweat, sunscreen, and oils. That means more stuff in the water and more work for your chlorine.

d) Yard Work & Pollen. Cut the grass or trim a tree near the pool? That stuff can blow right in. Same with pollen or nearby construction dust. 

So How Do I Start to Fix My Cloudy Pool?

Wondering why is my pool still cloudy after shocking it. Good question! We’ll save the full step-by-step for another blog. But here’s what you should know right now:

1. Don’t Guess. Test!

Guessing wastes time and money. If your pool is cloudy, use a good water test (not just strips). Or take a sample to a pool store, they’ll test it better. Do home remedies for cloudy pool water to treat it yourself.

2. Balance First, Then Sanitize

Don’t dump in chlorine first. Make sure pH, alkalinity, and calcium levels are right. Then your chlorine can work better.

Think of it as building a house. You need a level floor before putting up walls.

3. Shock and Filter

Here’s how to clear up a cloudy pool. “Shocking” means adding lots of chlorine to break down bad stuff in the water. But shock alone doesn’t clear the water. You still need your filter to run 24/7 to catch all the leftover bits.

4. Remove Debris Actively

Brush the pool walls, steps, and floor. This keeps stuff floating so the filter can grab it. A pool cleaner helps a lot with this, too. 

For a complete walkthrough, read: How to Clear a Cloudy Pool: Step-by-Step Guide

The Takeaway

Cloudy, murky pool water doesn’t mean your pool is broken. It’s just trying to tell you something’s off. And now you know how to listen.

Let’s quickly recap the reasons. Reason number one is due to out-of-balance chemicals (especially chlorine and pH). The second reason is that your filter system isn’t doing its job, and the third reason is that the outside stuff (like rain, dust, or swimmers) has added too much gunk.

Now you’re not guessing, you’re solving the real issue, like a pool pro. You got this!