Why Do Swimming Pools Turn Green?

woman swimming in green swimming pool water

Are you one of the 10.4 million people in the U.S. who owns a pool? If you currently have a pool, you might wonder, why do swimming pools turn green?

In this article, explore the reasons why your pool might be green and how to prevent it. Read on to discover what’s causing it and get treatment today!

1. Algae

One of the top reasons for green pool water is actually algae. Algae spores are deposited into your pool from the rain and air. Local runoff can cause spores to head into your pool as well. 

To properly get rid of algae, you’ll want to contact a pool professional today. 

2. Your Pool’s Pump and Filter

If your pump and filter are too small for your pool, this is what can cause the buildup of algae. If your pump and filter are the correct sizes, but you don’t run your filter every night for long enough, it can encourage algae growth. 

Another reason could be a clogged filter. If your filter is clogged, it won’t get rid of debris and algae. When your filter isn’t working properly, it can cause algae, fungi, and other molds to grow. 

Ensure you’re regularly cleaning your filter. For most pools, you should be able to remove the filter and clean it with water. Make sure you use a scrub brush to remove the particles. 

3. Oxidized Copper

While this is rarer, it’s another reason why your pool water turned green. This occurs when your pool water is in contact with copper. This can happen from corrosion in copper heaters. 

4. High Phosphate Levels

High phosphate levels feed algae. They can be found in pools from fertilizer runoff and detergents. High phosphate levels also decrease the job that chlorine does. 

Many pool tests don’t test for phosphate levels, so always ask a pool expert to test it.

5. High pH Levels

You’ll want your pool to have a pH level between 7.4-7.6. You can find high pH levels more common in saltwater pools than other pools. Saltwater pools actually create chlorine that causes a high pH if you’re not watching it closely. 

Does Chlorine Kill Algae?

Chlorine does kill algae and give you a clean swimming pool. Anything that lives in your pool, chlorine can kill. There are many other factors that go into whether it’ll do the job or not. 

For example, if there are high cyanuric acid levels in your pool or high pH levels, they can decrease chlorine’s job and impact water treatment. You’ll want a top pool chemical service for your pool.

Exploring Why Do Swimming Pools Turn Green?

You’ve explored why do swimming pools turn green? Now that you’ve found out why you can get to the bottom of your green pool.

Do you need help with getting your pool back to normal? Check out our swimming pool services, and we’ll make sure your green pool water is a thing of the past.