How to Clean a Pool that Turns Green with Algae

The season of swimming is almost here, and many pool owners are likely uncovering an unpleasant surprise: their pool turning green. If you’re one of the unfortunate ones finding that your pool is green and cloudy, it’s understandable to be grossed out. Especially with summer around the corner, and you’re wanting to invite guests over soon.

Whether you’re a long-time pool owner and this has happened to you before, or you’re a new pool owner, don’t panic! It’s a common problem that can be easily resolved with the right tools and techniques. 

First, though, it’s helpful to know why this happens. Keep reading to find out why your pool water is green in the first place.

Why Do Pools Turn Green?

Pools turn green due to the growth of algae. Algae are tiny aquatic plants that can grow in swimming pool water when conditions are favorable. Warm temperatures, sunlight, nutrients like phosphates and nitrates, and rain all contribute to algae growth. When these factors are present, it throws off the chemical balance. If not properly managed, algae can quickly multiply, the concentration of which turns the water green. 

There are several types of algae that can grow in swimming pools, but the most common type is green algae. Green algae can make the water appear cloudy or hazy and give it a greenish tint. In severe cases, the water can turn a solid green color, making it difficult to see the bottom of the pool.

Is it safe to swim in green pool water, though? While it’s not likely anyone has any desire to swim in murky green pool water, it should also be avoided because of the health risks involved. Swimming in water contaminated with algae can cause skin irritation, eye irritation, respiratory issues, and even infections. Additionally, algae can make the pool surface slippery and increase the risk of falls and injuries.

How to Clean A Green Pool

Whether you do it yourself or hire a pool maintenance company, here are the steps on how to get rid of green algae in pool.

Test the Water

The first step to cleaning a green pool is to test the water. Use a test kit to check the pH, alkalinity, and chlorine levels. Algae thrive in a high pH environment, so if the pH level is above 7.6, you’ll need to lower it. Otherwise, it’s just going to keep happening. If the chlorine level is low, you’ll need to shock the pool with a high dose of chlorine. Also make sure your filtration system is working properly.

Brush the Pool

Once you’ve tested the water, the next step is to brush the pool. Use a stiff brush to scrub the walls, floor, and steps of the pool. This will help to remove any algae that has attached itself to the pool surface. Make sure to brush the pool thoroughly and pay special attention to areas that are shaded or have poor circulation. This is a key step in how to clear a green pool.

Vacuum the Pool

After brushing the pool, use a pool vacuum to remove the dead algae and other debris from the pool. Start at the deep end of the pool and work your way towards the shallow end. Be sure to vacuum the pool thoroughly, paying special attention to areas that are hard to reach, such as corners and steps.

Shock the Pool

If the chlorine level is low, you’ll need to shock the pool with a high dose of chlorine. Follow the manufacturer’s instructions to determine the correct amount of chlorine to add to the pool. It’s best to shock the pool at night when the sun is down, as sunlight can cause the chlorine to break down.

Run the Filter

After shocking the pool, run the filter for at least 24 hours to remove any remaining algae and debris from the pool. Check the filter regularly to make sure it’s working properly and clean it as needed.

Retest the Water

After running the filter for 24 hours, test the water again to make sure the pH, alkalinity, and chlorine levels are balanced. If they’re not, make any necessary adjustments and retest the water again.

Maintain the Pool

To prevent the pool from turning green with algae again, it’s important to keep on top of pool maintenance. This is a year-round task, not just during the summer season. Clean the filter regularly, and keep the pH and chlorine levels balanced. You should also brush and vacuum the pool at least once a week. If you have a lot of trees or other vegetation around the pool, consider using a pool cover to keep debris out of the water.

If you don’t want to or have time to do it yourself, there are many excellent pool maintenance services that will assist you. Either way, if you stay ahead of maintenance, you’ll be able to enjoy a clean and clear pool all season long!