Person doing handstand in a dirty green pool

Green Pool Got You Down?

The summer is flying right by and we cannot believe it is already August. Thankfully, we still have plenty of fun in the sun ahead of us, and whether you were ready two weeks ago or not, the kids still have half of their summer break left. Around this time of the summer, we often see many people dealing with the same, ever-so-irritating situation–a green pool. Lucky for you, we are here to tell you exactly why your pool is green and how you will make it look good-as-new!

So, why exactly is your pool green?

When the chlorine in a pool drops below 1 ppm, algae often grows. When algae grows in a pool, it will obviously begin to change color. In order to get rid of the algae, you may need to “shock” your pool. In other words, you will need to super-chlorinate the pool because chlorine kills algae. For regular pool upkeep, one lb of hypochlorite granular chlorine (calcium hypo-chloride) for every 10,000 gallons of water is necessary for shocking. During an algae infestation, it is going to take a lot more.

The water is probably one of three colors:

  1. Teal–this is the least adverse of the greens. In order to shock a pool of this shade, you will need 2 lbs of calcium hypo-chloride for every 10,000 gallons of water.
  2. Green (may appear swampy)–this is slightly serious, but don’t fret. This color calls for 3 lbs of calcium hypo-chloride for every 10,000 gallons of water.
  3. Black–if you have a black pool, it may (it will) need more work, or 4 lbs of calcium hypo-chloride for every 10,000 gallons of water.

Professional Pool Cleaning Company - Pool ScoutsProcess Break Down:

  • Before shocking, you will need to test the chemicals to ensure that the pH balance is between 7.4 and 7.6 and the alkalinity is between 100 ppm and 150 ppm. You will also need to make sure the filter is running.
  • Shocking should be done at night. To begin, pour the bag of calcium hypo-chloride into a bucket of pool water.
  • Next, evenly disperse the mixed bucket around the perimeter of the pool.
  • Once the first attempt is complete, wait until the morning to decide whether or not a second shock is necessary. If so, repeat the process.

Stay in Control:

  • After you’ve shocked once or twice, the pool will appear cloudy instead of green. At this point, you will keep the filter running and watch for a rise in filter pressure.
  • If the pressure rises 20-25%, clean or backwash the filter.
  • Continue to test the chemicals to make sure that the pH levels are between 7.4 and 7.6, the alkalinity is between 100 ppm and 150 ppm, and the chlorine reading stays between 1 ppm and 3 ppm.
  • Keep the filter running 24 hours a day. When the cloudiness fully clears up, take it down a notch and only run the filter for 15 hours a day.
  • Don’t forget to continue balancing your pool water weekly. Cyanuric acid (CYA) is what we add to chlorine in order to stabilize the water because it protects chlorine from the sun’s UV rays. This makes free chlorine levels last much longer. If CYA levels are low, the sun dissolves the chlorine. This will cause the need for you to add chlorine more often. However, if there is too much CYA, the chlorine will lose some of its necessary sanitizing properties. In order to keep your pool properly balanced, CYA levels should never surpass 50 ppm, and chlorine levels should always be about 7.5 percent of CYA levels.
  • Of course, always empty the skimmer baskets a few times a week.
  • Finally, you go back to only running the filter 10-12 hours a day.

Once the pool is back to normal and the water is glistening in the sunlight once again, the job should be done! You may choose to add an algaecide weekly to keep your pool sparkling, but this is up to you. Good luck from Pool Scouts!


Pool Scouts is a premier pool service franchise focused on delivering a quality, consistent brand experience while providing pool cleaning, maintenance and minor repair services at residential properties. Technicians are trained in testing, monitoring, treating and servicing pools and can provide ongoing service as well as help at the beginning and end of the summer season. Growing from its first location in Virginia Beach, Pool Scouts offers a great opportunity as a low cost franchise in the pool services industry with available territories across the United States. For more information or franchising opportunities, visit