How To Clear Up Green Pool Water – High Chlorine, Shock & Fix (2020)

I have always been interested in how things work. As a kid, I would toil away on the filters in the pool in our Florida home. The filter is an example of immaculate engineering and helps you keep your pool clean and healthy. But sometimes, despite your pool filter’s best efforts, your pool becomes a green pool and the water murky and cloudy. At Pool Cleaning Expert, the website I started with a friend, deals precisely with situations like this, and offers tips to maintain your pool’s hygiene. Below is how you can clean green pool water, dirty looking pool in under five days, and be swim-ready for warm weather. But before we start, let’s get the basics out of the way!

What Makes Green Pool Water?

Your pool is probably green because of a buildup of algae. Algae in themselves are not toxic but can become the harboring ground for a lot of harmful microbes and cause infection. More than anything else, it is just slimy and gross to swim in. Algae buildup could be for a variety of reasons. Perhaps the phosphate and nitrate content in your pool is high. But it is not something that cannot be treated easily.

Check Your Green Pool

The first thing to do when you notice the green pool water in your swimming pool: you must try and ascertain why that may be happening. You know it is an algal bloom, but what allowed the algae to grow in your pool? If you can figure out what is causing the algae to appear, you can take measures accordingly instead of spending money on deploying the wrong solution. Check the following things:

How to clean a green pool – Filter

Check your filter to see if anything is blocking it and preventing it from doing its job. It could be leaves, sand, or dirt. If there are any blockages, clear your filter out. You can even backwash the filter to ensure it’s completely unobstructed. It’s essential to check your screen regularly to see if all is in order. If neglected, the filter may get blocked, causing the water to get cloudy.

Pool water is green – Chemical Levels

You will need to check the chemical levels in your pool. You can use a chemical test kit to see what the reading of your pool is. The test will tell you your chlorine and pH levels. The chlorine levels need to be at least one ppm on average. You can correct the pH levels of your pool by adding either a pH increaser or decreaser, whichever you require.

Turn on your filter when you add the chemical, so it gets properly mixed. Maintaining the right chemical levels is essential not only for the water but also for those swimming in the pool. You don’t want to take back skin infections and abrasions from acidic water, do you?

Green pool water after shock – Walls and Floor

Brush the algae off the wall and floor of the pool using an algae brush. This will loosen up the algae, and it will be released into the pool, making it easier for the chemicals to kill it. If the algae are lodged onto the walls, it’ll be harder for the chlorine to do its job.

My pool is green – Shock It

The next step is to shock your pool. This involves adding at least three times the average amount of chlorine and pool sanitizer into the pool.

There are a few things you may want to keep in mind when shocking your pool, however:

  • It’s better to shock your pool at night to prevent the ultraviolet rays of the sun from interacting with the chlorine.
  • Always add the chemical to the green pool water and not the other way round.
  • Dissolve the chemicals in a bucket before adding them to the water. Most pool chemicals come in a granular form, so they should dissolve easily.
  • Turn on the filter when adding the chemicals. Try to pour the chemicals on top of a return line fitting so the water pressure can carry the chemicals and allow them to mix.
  • You should pour the chemicals slowly so they can dissolve into the green pool water instead of collecting at the bottom of the pool.

Vacuum the Dead Algae When The Pool is Green

Once you are done shocking the green pool water, the chlorine will kill all the algae. While the filter should clean the dead algae out, to be sure you can also manually vacuum the pool to ensure you get the perfect clean. Since you can see more clearly now, use the algae brush to brush the sides and floor of the pool again. Ideally, the brushing should happen before you vacuum the pool, so any remaining pieces of algae can get pulled in by the vacuum.

This could be slightly time-consuming and tiring, but it will ensure your pool is crystal clear.

My pool is green but chlorine is high – Check Chemical Levels Again

Most importantly, you will need to check the chemical levels once again after shocking your green pool as swimming in a pool where the chlorine content is too high is dangerous. Use another chemical test kit to ensure the levels are right. The appropriate levels for a hygienic swimming pool are:

  • Chlorine:0 – 3.0 ppm
  • pH:4 – 7.6
  • Alkalinity: 80 – 140 ppm
  • Calcium Hardness: 200 – 400
  • Cyanuric Acid: 25 – 50 ppm
  • Total Dissolved Solids: 500 – 5000 ppm

Why is my pool green – Final Thoughts

So that was a sure shot method to get algae out of your green pool in under five days. It takes some effort and patience on your part, but the result is a crystal clear pool. But what’s important to do is maintain the hygiene of the pool. Don’t become lax after cleaning the pool only once. You cannot expect your pool to maintain its sanitary levels on its own. It is your responsibility to ensure you maintain your pool regularly. Shock your pool at least once a month to prevent algae from coming back. You should also maintain your pool chemical levels to ensure the algae doesn’t even get the chance to appear in the water.