Answer
Sep 08, 2025 - 10:58 AM
If your pool water keeps turning green even when you add chemicals, it usually means the water chemistry isn’t properly balanced or the sanitizer isn’t working effectively. The most common cause is algae growth, which happens when chlorine levels are too low, unstable, or blocked by other factors. In some cases, metals like copper or iron can also turn the water green even if algae aren’t present.
To correct the problem, you’ll want to start by testing your water so you can check free chlorine, pH, alkalinity, stabilizer (CYA), and possibly phosphates or metals. If chlorine levels are low or not working because of high stabilizer, you’ll need to shock the pool, which means raising chlorine to a very high level to kill off algae. While doing this, make sure to brush the pool walls and floor so algae can’t cling to surfaces, and run your filter continuously to remove the dead algae from the water.
If the water stays green but looks clear, metals may be the cause, and adding a sequestrant can help bind them so they don’t stain the pool. Finally, be sure your filter is clean and running long enough each day, since poor filtration makes it harder to keep the water clear. Proper balance of chemicals, consistent filtration, and occasional shock treatments will help keep your pool from turning green again.
To correct the problem, you’ll want to start by testing your water so you can check free chlorine, pH, alkalinity, stabilizer (CYA), and possibly phosphates or metals. If chlorine levels are low or not working because of high stabilizer, you’ll need to shock the pool, which means raising chlorine to a very high level to kill off algae. While doing this, make sure to brush the pool walls and floor so algae can’t cling to surfaces, and run your filter continuously to remove the dead algae from the water.
If the water stays green but looks clear, metals may be the cause, and adding a sequestrant can help bind them so they don’t stain the pool. Finally, be sure your filter is clean and running long enough each day, since poor filtration makes it harder to keep the water clear. Proper balance of chemicals, consistent filtration, and occasional shock treatments will help keep your pool from turning green again.
