How to Remove Algae From a Salt Water Pool

There is no huge difference between a salt water pool and swimming pool with regular chlorine. You may think it would be harmful if you add chlorine into a salt water pool. But it is not in this case.

Most saltwater systems are produced with a button or switch to allow you to “super chlorinate” water in the pool. However, this feature is not a replacement for chlorine shock. To oxidize your pool, you may need something stronger than “super chlorination”. In fact, it is still necessary to do super chlorination monthly, but it will be not effective enough to help you get rid of algae. In order to clean up algae in your pool, you have to use the conventional shock which is considered as the best pool cleaner and shock your pool weekly.



It is really uncomfortable when seeing the algae in your saltwater pool. There are four things you need to focus on to change the situation of your pool

The rate of pH and alkalinity in your pool

The amount of shock

Your filter system

And your efforts

You can clean your pool yourself by following these appropriate steps below


Shock Your Salt Water Pool

First, you need to test your water yourself with test strips or take a water sample to your nearest pool supply store, if you think you do not understand the checking method. Ensure the levels of your pH and alkalinity of your pool are correct. You would want your pH to be around 7.4 to 7.6 and the alkalinity to be between 120 and 150 ppm (parts per million).

Hint: The shock will work more efficiently if your pool water is properly balanced.

Before shocking, the best preparation is brushing the walls and floors of your pool by the pool brush. There are cases that algae will cling to the surfaces of your pool, but by scrubbing the bottom and the sides, if you break it up first, then the chlorine shock will have a better chance to kill it. You need to pay particular attention to some hard-to-clean spots such as crevices, behind ladders, creases,  and pool steps.

Then, you need to determine the colour of the pool by the algae. If your saltwater pool is light green or teal, then you should double shock your pool by using standard calcium hypochlorite shock.

10,000 gallons of water would cost you one pound or bag of shock to treat up. Therefore, if your pool is about 10,000 gallons or less, you would need two pounds of shock to your water. It would be more effective in adding shock only at night. In addition, keep your pool running for at least 8 hours to allow the shock to circulate throughout the water and kill the algae.

It’s a saving-money idea to buy your shock in bulk instead of buying the retail one and so it’s always on hand when needed. This shock has a very high rate of active chlorine which is truly powerful for killing algae. Remember the tip is always shocking your pool at night when the sun is gone to get the best result.

If your saltwater pool is green or dark green, you should use a triple shock. This means you should use three pounds of shock if your pool is 10,000 gallons or less.

If your pool turns to black from algae (this case is quite rare and only happens at the beginning of the year of if you neglected your water salt pool for weeks or months), then you will have to quadruple shock it using four pounds per 10,000 gallons of pool water.

After Shocking, Your Pool Should Be Cloudy Blue

blue cloudy pool water after shocking

After the shocking process, you would see a cloudy blue pool in the next morning. This is the exact result we want. The dead algae usually lead to the cloudy water, which turns to a light grey when it’s killed. Then, your filter would do the rest.

Keep your filter running 24 hours a day during the process until the pool is totally clear. You can consider your filter as a best robotic pool cleaner since you only need to use it to know whether any debris stays in your pool without using other machines. It’s also safe to swim in your pool if it is cloudy. The movement in the water will help the filter clear the dead algae way.

Your Pool Is Still Green

If your pool is still green or teal from algae, you may need to repeat the shocking process to get rid of it for good. That why I would recommend buying enough shock to do this twice in case this happens. You should do the process again in the very next night. Then, the pool water would become cloudy blue and you can start to clean it up again.

If your pool still not turn to cloudy blue after the twice shock, there may be other problems with your water chemistry. Here are some things to solve this situation:

  • Make sure your pool water is balanced in a suitable way.
  • Check your water again before shocking by the support of a local pool store.
  • Have the store staffs check for chlorine lock or chlorine demand of your pool if they can.
  • Only execute shock process at night or dusk
  • Keep your filter running during the shock process.

How To Prevent Algae from Growing

The key are always controlling your pool properly balanced and sanitized to keep the algae from growing or returning. Make sure you follow these tips:

  • Keep the levels of pH, alkalinity and sanitizer in the correct rate at all times by periodic check.
  • Run your pump and filter about 8 to 12 hours a day.
  • Keep your pool clean and safe from the algae by regularly vacuuming and brushing.
  • Shock your pool every week. Remember 1 pound per 10,000 gallons or less.
  • Keep your other pool equipment clean including pool toys, diving boards, slides, floats, ladders, steps, diving boards, slides, solar blankets and covers.


Having the algae in your saltwater pool can upset you a little bit, but with just a little bit of hard work and some simple steps, you can easily and smoothly clear away the algae from the water and bring it back to the original situation that you wish to see in your pool.

Enjoy your swimming!