Sometimes, pools can turn a ghastly green shade that nobody wants to swim in. If you haven’t cleaned it for a while, you might even find frogs and tadpoles in the water.
However, having a green pool isn’t a reason to panic. There are ways to clean it fast if you have people coming over in a few days.
Hang tight, read this article, and get ready to transform your pool into the talk of the town — for its refreshing blue tint and pristine waters.
Why Do Pools Get Green?
Before discussing specifics, it’s essential to understand why pools get green. While pools can turn green for a number of reasons, there’s typically one culprit during such circumstances: algae.
If your pool has turned a light green hue, the algae have likely started taking hold of your tiles. However, a deeper green shade signifies a more serious infestation.
These conditions are ideal for algae growth:
- Temperature changes: Algae thrive in warm, humid conditions. They love hotter temperatures of at least 85 degrees. During seasonal transitions, like from spring to summer, it’s best to be extra diligent about cleaning your pool.
- Improper pH balance: A pool’s pH level is critical for the structure and the people using it. A low pH in a pool can cause damage to your equipment, but high pH content will not kill algae. Finding the right pH intensity can help you keep your pool looking and feeling safe.
- Clogged filter: When your filter doesn’t work as it should, you have to work double-time to keep your pool clean. With a clogged filter, you won’t only have to deal with algae but also with breeding bacteria and debris.
No matter the cause of the algae growth, the solution is the same. Read on to discover how to get your pool back in tip-top shape.
How to Clean a Green Pool
So, are you ready to turn a green pool blue fast? Follow this step-by-step guide to achieve your pool goals.
Step 1: Test the Water for pH and Alkalinity Levels
You can either use test strips or a liquid test kit to check your pool’s pH and alkalinity levels. Take note of the results, as you’ll need them again later.
You can also list the chlorine levels or other sanitizers. In most cases, when these chemicals go too low, algae will start growing.
Step 2: Vacuum the Pool
Check the pool for visible signs of debris, brush walls, and empty skimmer baskets. Focus on areas with high dirty levels and with little or no circulation.
Naturally, when you start removing the algae and dirt from your pool, you don’t want anything creeping back in. Set your vacuum to waste, clean your pool, and remove as much sediment from the bottom as possible.
Check out our top picks for the best pool vacuum cleaners.
Step 3: Brush Pool Surfaces
When dealing with a green pool, use an algae brush instead of your usual tool. Algae are tough organisms that will stubbornly cling to your pool walls, so choose heavy-duty brush materials over soft nylon ones. Brush the walls, floors, steps, and other surfaces where you might find algae.
Step 4: Apply a Shock Treatment
Pool shocking is the process of adding chlorine chemicals to reach the ideal free chlorine level. Ultimately, the goal is to achieve an amount that will kill contaminants like algae, chloramines, and bacteria without harming the pool or anyone using it.
Even if you often use non-chlorine products to shock your pool, chlorine works best in killing algae. Use products with at least 70% available chlorine for this process. For best results, shock your pool twice.
Step 5: Use Algaecides
The right algaecides can help you treat your pool and prevent future algae growth. Use products particularly designed for green pool algae. When you still see dead algae after treatment, keep brushing surfaces to get rid of them.
Step 6: Activate Your Filter
Before using your filter, clean it according to your manual to remove any build-up. Afterward, turn the filter on and keep it running until the water is crystal clear. Even if you use a pool clarifier to speed up the process, keep your filter on for at least 24 hours to get the dead algae out of the water. Note, you may need to shut your system off and backwash your pool filter a few times during this stage. While backwashing, you can watch the green water come out of the hose. Once it turns clear, you’re good to turn the system off and switch the filter back on.
Step 7: Test the Water Again
When your pool has turned blue again as it should, test the water again. Apart from checking pH and alkalinity levels, inspect the sanitizer intensity as well. Balance everything out so you can start enjoying your pool again.
How Long Does It Take for a Green Pool to Clear Up?
Cleaning a green pool can be a fast process, but it requires a lot of work, especially if you have full-on algae bloom on your hands.
In less severe cases, you can clean your pool within one to two days. However, the process might take longer for worse infestations. You will notice improvements in dark green pools within the first 24 hours, but it might take four to five days to free them of algae completely.
Why Is My Pool Still Green After Shocking It?
When you find your pool still sporting a green shade after shocking it, don’t worry. It’s not as uncommon as you might think. Below are some of the top reasons why it happens:
- Metals in the water: When your pool contains metals like copper, it will immediately turn green after a round of shocking. These metals oxidize upon chlorine exposure. The solution is to use metal control products to restore your pool.
- Copper-based algaecides: Using copper-based algaecides can boost your pool’s metal levels and turn it green. You may also use metal control products for this scenario. In the future, try using metal-free algaecides instead.
- Unstable cyanuric acid (CYA): CYA stabilizes the chlorine in your pool and protects it from the sun’s rays, but high levels can prevent the chemical from killing algae. Keep your CYA level in the 30 – 50 ppm range to prevent it from turning the water green.
- Phosphate content: This chemical compound provides algae with food. If you want to cut these organisms’ food supply, keep your phosphate levels below 500 parts per billion or ppb.
- Flocculant use: If you still have problems seeing the bottom of your pool after shocking it, you can use a flocculant to remove the dead algae. It’s fast and effective at removing dead algae, which should clear up your pool.
These techniques should help you achieve a crystal clear pool in no time.
Keeping Your Pool Algae-Free
Now that you know how to clean your green pool fast, it’s time to learn how to maintain its cleanliness. Here are a few simple steps to achieve such a feat:
- Check filters and pumps regularly. Stagnant water encourages algae growth, so make sure your cleaning systems work properly.
- Brush and vacuum once a week. No matter how tedious the process seems, keeping your pool clean prevents algae and other bacteria from thriving in it.
- Maintain a healthy pH level. Check your pool’s pH and chlorine levels two to three times weekly. Ideally, you should keep it between 7.4 and 7.6 to stave off algae spores before they bloom.
- Cover your pool. Using a cover keeps out debris and other organisms that might turn your pool green. Additionally, it prevents the sun from supercharging any algae growth.
There’s one culprit to your green pool: algae. The good news is, when this happens to you, all is not lost. You don’t even have to drain your pool to get rid of the organisms.
There are ways to clean your green pool fast, including vacuuming and scrubbing surfaces and using treatments. Once you turn the water back to blue, remember to take care of your pool better to prevent algae from growing again.
About the Author
Stefan Schulz is the founder and owner of PV Pool Cleaner. He spent his college years working at Niagara Pools and Spas, one of the largest Swimming Pool and Hot Tub Dealers in the Eastern United States.
Today, he utilizes his background, experience as a pool owner, and the resources of his digital marketing agency, Orpical Group, to generate informative and engaging content for pool owners everywhere.