Green pool water is often caused by the presence of algae in your pool. Algae blooms can appear when your pool has a low Free Chlorine. Exposure to high heat, heavy rain or poor circulation, without the use of a preventative algaecide, also increase your risk of developing pool algae.
The free chlorine levels might be low.
But be careful—adding too much chlorine in pool water can cause those metals to oxidize and turn the pool a different shade of green.
Baking Soda and Green, Blue, or Yellow Algae
You'll need to use an algaecide to kill the algae and superchlorinate your pool to clear the water. After this treatment, test your pH and alkalinity and add baking soda to raise alkalinity to at least 100 ppm and pH to between 7.2 and 7.8.
Pool water turns green because of algae in the water. Algae can grow rapidly, particularly when it's warm like Summer, which is why it can surprise you overnight. This generally comes down to an imbalance or lack of chlorine in the water.
While the green algae aren't harmful, the bacteria that feed on the algae can cause issues. When you swim in green water, you expose yourself to algae that host bacteria. Swimming in green water could cause bacterial infections on your skin, and you could get sick if you ingest algae-filled pool water.
Light Green or Teal Pool Water:
In this case, you should double shock your swimming pool water. To double shock, you will need to add 2 pounds for every 10,000 gallons of water. For instance, if you pool is 20,000 gallons, you will add 4 pounds of shock.
In theory, if you have a cloudy swimming pool, you can add chlorine to “shock it” and clear things up. Chlorine will get the job done. But, the amounts may vary and you may have to really pound the pool with chlorine to get the water totally clear.
Although, if you overdo the shock treatment, you risk getting green hair from chlorine due to the excess chlorine oxidizing the copper in the water. You can execute a shock treatment with a few different types of pool shock, just be mindful of how much you're using.
Algaecide should be used after each shock treatment, so it has a better chance to support your chlorine as it works its magic. Be sure to shock your pool first, then when the chlorine levels of your pool return to normal, add the correct amount of algaecide to several places around your pool while your pump is running.
ADD POOL CLARIFIER
The change in your pool water colour means that you have successfully eliminated the algae and can now clean it out of your pool. If your water is still green, wait another 24 hours and redo the steps from Days 1 and 2.
Why is my pool green? Typically, algae is the source of green pool water, and it's certainly possible that it took over quickly, even overnight. This is especially likely if it is very warm outside, since algae blooms more rapidly in warmer temperatures.
You need to raise the level of your chlorine – shock the pool – and maintain that high level until all the algae is dead. This may take 3 to 4 days.
The presence of too much algaecide can lead to a foamy pool water. Small bubbles will begin to be produced as the water is pushed through the return jet and back into the pool. Do not confuse these bubbles and foam with another common problem, which is air in your pool lines.
Chlorine—yep, your typical sanitizer—is much more effective at killing algae than algaecide is. Even if your water gets cloudy and your walls get slimy, chlorine can still kill it. That's because chlorine oxidizes bacteria and single-celled algae, which means they trade electrons.
Backwash only as needed. Brush the pool vigorously, several times after shocking the pool. Do not use a solar blanket until chlorine and pH level are normal. If chlorine level drops to zero within 24 hours, Repeat the shock treatment.
Pools can immediately turn green after shocking when they have metals like copper in the water. These metals oxidise when exposed to high levels of chlorine which makes the pool water turn green. Adding a metal control product such as Zodiac Metal Remover will help to restore the pool water.
Chlorine is a sanitizer, and (unless you use Baquacil products) is necessary for maintaining a clear and healthy pool. Shock is chlorine, in a high dose, meant to shock your pool and raise the chlorine level quickly.
It's pretty tough to over-shock your pool; shocking your pool two days in a row with the proper dosage for your pool volume shouldn't be a problem – and in fact, is sometimes even needed to rid your pool of algae and other contaminants.
Baking soda can work wonders in a pool. Baking soda can: Help to clear cloudy water and restore the sparkle. Spot-treat algae.
Fill the pool, and add the bleach and borax. Wait an hour, then use the strips to test. The chlorine level should be 3.0 or higher, and the pH should be 7.4 or higher.