how to fix a green pool

Many pool owners will face a green pool in their backyard at some stage of ownership. This is particularly true right after the off-season, as pool owners will commonly neglect their pools during the cooler months. Thankfully, you don’t have to be a rocket scientist to fix your green pool. If it’s not too far gone, then you can simply do it yourself and not worry about calling in a professional.

Let’s get stuck into it. What causes a green pool?

To sum up the answer in one word: Algae. This green organism is given the chance to build up in your pool when there is a chemical imbalance; when you haven’t scrubbed and cleaned your pool’s surface properly; and, when your pool water isn’t being circulated enough.

Clean green Pool

You really need to take care of your pool water consistently to avoid having this problem. Also, fixing a green pool isn’t quite as simple as just adding chlorine. There are steps you need to take in order to get your pool back to its sparkling best. So, without further delay, let’s get into those steps.

Step 1: Determine if your pool water is too green.

If you’ve really skipped on pool maintenance throughout the year then your only option may really be to call in a professional. The best way to determine if you’ve let your pool go too far is to check how far below the surface you can see. If you can see between 20 and 30cm into your pool then you should fix your green pool by yourself.

Step 2: Test your pool water.

The next thing you need is to test your pH level. Your pH level should be below 7.2, so that you may effectively shock your pool. If it’s not, then add muriatic acid to lower the pH level – about 4 liters should do the trick. Allow your pool water to circulate for about 4 hours and then test your pH levels again. It’s important to note that if your pH levels are higher than 7.2, all you’ll do is create a cloudy pool by adding too much chlorine.

Step 3: Add lots of chlorine and shock your pool.

chlorine for green pool

First, turn on your filter – it’s important that your pool water is circulating. Next, evenly distribute approximately 2.5kg of granular chlorine across the surface. You can also use liquid if you prefer. You will need 5 liters. You can now take a rest, as you let your water circulate for a few hours. When you return to add some algaecide and also feel free to add in some flocculant as well so that all the dead algae will clump together. It’ll make things easier later on.

Step 4: Let your filters and pumps do the heavy lifting.

How you approach this step depends on the kind of pool filter you have – a DE filter, sand filter or cartridge filter. The process for each is explained below:

DE Filter:

First, backwash your filter and then add in some DE powder. Now fun your filter for 24 hours, though ensure there are no leaves or debris near the pool drain.

Sand filter:

Here you’ll do the same thing as with a DE filter, though backwash your sand filter for at least 5 minutes.

Cartridge filter:

Consistently change your cartridges and rinse your filter, ensuring its in great condition until your water clears up.

Step 5: It’s time for manual labor and more filtration.

Your water should look completely transformed after about 24 hours. It’s now time to apply some elbow grease and get scrubbing. You’ll be doing this over the next few days, getting rid of stubborn green spots as you go. If your pool water is a little cloudy at this stage, don’t be too worried. It will take a few days for the cloudiness to disappear depending on your filter. Allow up to about a week.

Step 6: Maintain your pool. Continue to keep your water crisp clean.

Now that you know how to fix your green pool, don’t undo all your hard work by letting it go again. The best thing you can do is to continuously maintain and clean your pool. Don’t forget about if it’s the off-season either! A little goes a long way. So, by doing a bit of weekly maintenance throughout the


Please enter your comment!
Please enter your name here