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How to Clean a Green Above-Ground Pool (Plus How to Prevent It)

How to Clean a Green Above-Ground Pool (Plus How to Prevent It)

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After neglecting it for some time, you’re excited to start enjoying your above-ground pool. But you’re met with the sight of cloudy and green water, and it doesn’t look so inviting. 

Something has gone bad, and now you must deal with the stagnant green water. So what should you do about it?

I’ll walk you through the process of cleaning the pool to restore the clear inviting color. If you want to know how to clean a green above-ground pool, keep reading. 

What Happened to My Pool Anyway?

The reason why your pool turned green is related to algae, as these microorganisms thrive in warm conditions. A neglected pool will be an inviting environment for algae growth when left without proper maintenance. 

When a swimming pool is clear, it is primarily free from organisms that might live in the water. It’s the result of proper water circulation and using potent chemicals. 

But when you don’t treat the water with chlorine or use an adequate filter, the pool becomes closer to a pond, where algae naturally thrive. 

How Do I Know That Something Is Growing in My Pool?

Above Ground Pool

Algae growth turns the water green too fast. These microorganisms reproduce so quickly that you will notice cloudiness well before you see any hint of green.

Since they’re so small, it’s already too late when you notice the cloudiness. You don’t want to wait any longer to look for a treatment!

When your pool already looks green, you know there’s a vast population of algae living in the water. The greener the pool, the more algae you will find in it.

How to Deal With Green Pool Water?

Adding A Chlorine Tablet To An Above Ground Pool

So, what is the most effective approach to kill the algae and enjoy crystal clear water?

Chlorine is the best treatment to shock an extensive algae growth. How much to use is determined by how big your pool is and how much algae is in it. So, it is not a one-size-fits-all solution.

But the goal is to shock the algae with the amount of chlorine you add to disrupt their life cycle. Various products available, like algae guard and pool shock, work fine.

You will probably have to pour at least a 2.5-gallon bottle of chlorine (or more) or several pounds of granules to achieve this result. I recommend buying the bigger containers to get the best value. 

It takes more time and product to eliminate all traces of the algae. You can even purchase 25 or 50-pound buckets of granules for long-term protection.

Read and follow the application instructions accurately. Moreover, you must use a reliable algaecide to prevent future growth. 

How to Calculate the Amount of Product Needed to Treat Pool Water

Start by calculating how much water your pool holds (it should be in your pool’s instruction manual). 

Read the application instructions and how much product you should use for this pool. Start there and see how it turns out. 

Too challenging? Try using a tool for an accurate measurement. Various free apps are available to do the math for you, like Pool Pal.

You should follow the protocol of letting your pump clean the pool for several hours and then check the pool’s chemistry. 

Don’t forget to clean the pump and filter in the meantime. That will help you decide how much algaecide and chlorine to add to get the water levels right.

How Long Will It Take?

There’s no doubt that if you use the right amount of chlorine, you will see a huge difference in 24 hours. But there are some considerations:

  • Your water is still likely to be cloudy and not clear. It may take your filters days or even a week to clean the water completely until crystal clear. 
  • Check your filters often during this period. You don’t want to stress the pump too much.
  • You may have stubborn green spots that must be scrubbed off. This is an essential part of the process of cleaning your pool and restoring the clear color of the water. 

How Do You Prevent It From Happening Again?

Testing Pool Water

You should admit that algae grow mainly because of ignoring your pool for too long. Seeing that the water is already green means you’ve probably stopped monitoring your pool for too long. 

Once you notice that the water is turning cloudy, you know algae are already growing in your pool. 

Yet, instead of waiting until you notice that the color of the water is changing, you can grab a water testing kit. 

Kits give you precise measurements of the water chemistry to accurately assess its status. The Taylor K-2006 is an ideal test kit to use with your pool.

Best Practices for Cleaning Your Pool

Cleaning your pool regularly is paramount. Consider these practices to help maintain your pool. 

The goal of this approach is to be proactive in cleaning your pool so you don’t have to deal with the green mess.

Brush Regularly

Brush your pool after applying an algaecide to ensure it has completely dissolved in the water. 

Brushing every corner of your pool will prevent the accumulation of algae. It can also facilitate the process of cleaning the pool when you use an algaecide. 

Start by brushing the nearby benches and steps before brushing the pool itself. Start from the end farthest from the drain, as the purpose is to push everything towards it eventually when you’re done. 

Scrub the walls and floors, and pay special attention to the corners. 

Use an Algaecide

Algaecides are treatments that prevent the growth of algae in pool water. Pick a good type and use it regularly to keep the water clear in your pool. 

An algaecide is best used as a preventative measure to maintain the cleanliness of your water. 

However, it’s not potent enough to remove the green color from your pool water. So, if the pool water is already green, it won’t work. 


Check all the parts of the filtering system in the pool to make sure they are running well. Your water pump and filter are the two primary items on this checklist and should operate flawlessly. 

Turn off the pump and open the filter’s valves. Inspect the cartridge for damage and use a brush to remove all the dust. 

Inspect the pump to see if the motor doesn’t work. It might be jammed with debris that prevents it from working adequately. 

If the filtering system parts aren’t working properly, you should replace them. 

Regular Testing

Testing is primarily done through pH testing kits. You should get your pH level around 7.4 to 7.6, but generally, 7.2 to 7.8 is acceptable. 

Any higher pH level will cause skin rashes, while a lower pH level will cause eye problems. High alkalinity can also lead to the formation of white algae. 

Using too little or too much chlorine will be bad for the water’s balance. So, don’t overdo it. 

Choose Your Chlorine Carefully

You can buy your chlorine at the grocery store, but purchasing the large containers available at pool maintenance stores is more cost-efficient. There are options for liquid chlorine, chlorinating tablets, or granules, so pick the most suitable one. 

Check the directions to calculate the recommended amount to add to your pool. I recommend buying larger containers than the regular household one-gallon bottles to save money and guarantee you have a potent product. 

People have different opinions regarding which chlorine type is best. A floating dispenser delivers the most consistent chlorine amount in your pool’s water and is a good choice for most pool owners. 

The goal is to keep chlorine in your pool water all the time.

Not Skimping on the Time That You Run Your Pool Pump

Don’t forget to run your pool pump for the recommended time. For the freshest pool water, some experts recommend running it during the daytime and turning it off at night. 

But this depends on the size of the pool and the pump’s power. Again, check the pool instruction guide for the needed time to keep your pool clean.

Doing Additional Cleaning

You might use enough chlorine to wipe out your algae, but you’ll probably still need to vacuum or scoop to keep it in the best condition. Use a skimmer to remove all the debris to keep your pool clean. 

Change the Filter

Backwash your filter or clean it before a shock process, but if it doesn’t work, you’ll eventually have to replace it. 

Most people agree that the DE filters cost more but are the most efficient. Others will work fine but may need to be cleaned more often to maintain efficiency. 

How Often Should I Clean My Pool?

Ideally, you should follow most of these steps every day to keep your pool water in top condition. Always follow a proactive attitude and prevent the growth of algae. 

You won’t regret it and will probably pay less over time. It will also prolong the overall life of your pool for your family’s enjoyment.

What If My Pool Has Moved Beyond Green to Brown or Even Black?

Dirty Above Ground Pool

This is a great question! Pools neglected for extended periods turn brown or black with sludge-like substances growing on them.

The bad news is that your pool can reach a point beyond where it can be shocked by chlorine with constant neglect. Unfortunately, chlorine won’t work at this stage. 

If you can’t see into the pool water because of how dark the water is, then you probably need to take further action. Some pools reach this point and should be drained and cleaned with acid to remove all the algae. 

Algae are caused by algae spores that can be brought into the pool through wind or swimmers. Here are the most common types. 

  • Green algae are the most prevalent. Thankfully, green algae are also the easiest to treat with chlorine. 
  • Yellow algae usually grow on the bottom of your pool. Some confuse this algae type with sand or a similar-looking substance. This kind of algae is more likely to develop if part of your pool is in the shade. 

You may need to purchase an extra chemical to eliminate this algae species. Yellow Out (available on Amazon) works great. But follow the instructions on the bottle for the best results.

  • Black algae are the rarest kind but also the hardest to treat. If you see black spots of different sizes, that is black algae. 

While other algae may live more on surfaces, these black algae patches attach deeper within the surfaces they cling to. You will need a brush in addition to strong chemicals to remove black algae.

Do it Yourself or Get Help?

Pool Cleaning Supplies

The stories of pool owners might be similar to those of boat owners. The two best days ever for a boat owner are the day he gets his boat, and the day he gets rid of it. 

Maintaining a boat is hard, and the same can be said about pools. So, in a way this makes sense. 

Many people think that the cost involved with pools is only related to installation. But all pool owners find out quickly that this isn’t true. The cost of equipment used to keep a pool clean can be quite significant.

As a result, every pool owner should be aware of the time, money, and effort needed to keep a pool free of algae. Brushes can go bad after a while, and you’ll have to purchase a consistent supply of algaecide and chlorine to keep these microorganisms at bay. 

You must also think of cleaning your pool as a daily routine, not an occasional practice. Most pool owners enjoy doing it and know that it will prolong the look and life of their pools.

However, this isn’t true for all pool owners. 

Some pool owners love the water but dread the daily cleaning of the pool. I’ve already highlighted the importance of cleaning the pool. 

But is it worth paying someone else to do it for you?

The following reasons show that it is a good idea to have someone assist you in maintaining your pool.

Speed and Efficiency

Professional pool cleaners work with speed and efficiency. There is no doubt that cleaning the pool takes time to master. But the more you do it, the better and faster you become. 

Some find that their pool professionals can do double the work. The results are also exceptional. 


Are you worried about the pool’s chemistry? Professionals know what to look for and how much chlorine to add. 

Determining the amount of chlorine to add might puzzle some pool owners. Professionals know how to calculate the right amount, and do so without wasting chlorine or time. 

They also achieve better results without adding more chlorine later when the right amount wasn’t used the first time. 

They Have the Right Tools

Worried about paying for special tools or equipment to clean your pool? Not when you hire professionals.

You’ll only have to provide the necessities like the pumps, skimmers, and chlorinators. A pool professional will have access to the more expensive tools you don’t want to pay for. 

Even if you don’t own all these necessities, they can bring them instead. 

You won’t have to give up quality in exchange for a better price because they will bring high-quality tools and equipment to clean your pool. Plus, their tools will lead to faster and better results. 

They Know How to Spot Algae

This article talks about dealing with a green pool. This is easy to spot, and you immediately know you have an algae problem. But what if the pool is cloudy?

Having a cloudy pool could be caused by algae growth or using too much chlorine. Only a professional will be able to tell the difference.

Unlike green algae, other types, like yellow algae, are challenging to identify. As a result, you won’t be able to determine the problem and its cause. 

It could be some sand the kids accidentally brought into your pool or some nasty yellow algae. 

Only pool professionals know what to look for, whether you are looking at cloudy water or yellow algae. Leave the diagnosis to the pool doctors.

They Know How to Maintain Your Pool Equipment

Is your pump having a bad day, or is the engine broken? Does the filter need to be cleaned, or do you need a new one? 

What is the average life of this type of pump? And how can you replace it? 

There are so many questions about your pool equipment, but you might not be able to find reliable answers. 

This is why it’s a good idea to have a pool professional to help you out with the maintenance, service, and replacement of your pool equipment.

Final Thoughts

Cleaning your above-ground pool is an excellent investment. It makes the pool healthier for you and your family, helps build a friendly community with neighbors, and even changes it to an inviting spot for your kids and their friends. 

But that’s not all. Maintaining your pool and getting rid of the green algae adds value to your house that yields results when you sell your home. 

It’s crucial to shock the pool and kill the algae, but once done, regular cleaning will keep algae growth at bay.


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