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.
Should the green be due to pollen, there may be little to do in the way of minimizing the discoloration short of erecting a building around the pool. Fortunately, assuming there are no allergies to the pollen, it is safe to swim in a pool with that as the cause for green water.
Shock Your Pool with Chlorine to Kill Algae
This is the main event in clearing a green pool—killing the algae. Pool shock contains a high level of chlorine that will kill the algae and sanitize the pool. For the best results, use a shock that contains at least 70% available chlorine (calcium hypochlorite).
The most common reason pool water turns green is due to algae growing in the water. Algae can grow rapidly, particularly in hot weather, which is why it can surprise you overnight during the warmer months. This generally comes down to an imbalance or lack of chlorine in the water.
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.
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.
Clorox itself recommends using between 100 and 200 ounces of regular-strength bleach per 10,000 gallons of pool water -- one gallon is 128 ounces, and many bottles of bleach are available in one-gallon or half-gallon sizes. Pool professionals tend to recommend more conservative amounts of bleach.
Just like you run vinegar through your coffee pot to get rid of calcium buildup, white vinegar can wipe away this eyesore in your pool. Mix a 50/50 solution of vinegar and water, dip a sponge or soft cloth into it, and scrub that residue away.
It is important to know what exactly bleach is before you put it in your pool. Household bleach, Clorox and liquid chlorine can all be used to sanitize a pool. They are all types of chlorine. Household bleaches such as Clorox usually contain about 5-6% available chlorine, about half that of pool liquid chlorine.
If your pool is green but chlorine is high, it's possible that you aren't running the pool's filter often enough or for long enough to filter out algae and bacteria. In spring and summer, when it's warm outside, pools should be filtered for eight hours a day, regardless of whether the pool is in active use.
The fastest way to clean a green pool is by using pool chemicals and your pool filter. This process usually takes around 4-5 days but you will start noticing a major improvement after 24 hours.
A pool turns green when there is algae in the water. There are several reasons why algae could grow, but it is most commonly caused by prolonged exposure to the sun, rain and temperature spikes. These factors affect the chemical balance of the pool and result in the pool turning cloudy and/or green.
After your cyanuric acid level is set, add the bleach. Then proceed with daily testing until you understand how much chlorine your pool uses. At this point, chlorine maintenance can be as simple as adding a little bleach to your pool every day to keep it within the target levels.
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.
There are alternatives to chlorine including bromine, ionizers, and ozonators, though with each you'll still need to use some chlorine. A fourth alternative is PHMB, which doesn't require the use of any chlorine. All four have drawbacks, including cost.
Natural Cleaning Agents for Pools
Baking soda: This is a great cleaning agent in general that also works well in swimming pools. The active ingredient in baking soda is sodium bicarbonate, which breaks up algae and allows you to scrub it and clean it from your pool.
Unlike chlorine, vinegar is non-toxic and can be used to get rid of algae in pools. It also destroys mold, weeds and other microorganisms.
Answer: It is true that pool chlorine is stronger than bleach. For bleach and water to be the same strength as pool chlorine and water, you would have to adjust the ratio, increasing the bleach and reducing the water. But no matter which chlorine you use, make sure to test a small area before doing the job.