If your water is clear and sparkly green then you have copper. Buy a 12lbs of Arm and Hammer baking Soda from Amazon (BUY IT HERE) and add half in your pool. Leave for 2 hours and your pool will return to its crystal-clear blue color!
Or it could be high Iron levels. The reddish iron color against a blue liner makes it turn green. The chlorine most likely oxidized metals. So, if you have a sand filter, it should clear on its own. The metal will simply precipitate out and get filtered. How do you know? Pay close attention to the next time you backwash. You should see a dark orangish colored water come out the backwash line.
ALSO SEE: What is the Best Umbrella for Pool Sleeve?
Why Does My Pool Turn Green When I Add Chlorine?
If you added a hypochlorite source of chlorine to your pool and it turns green almost immediately, then that isn’t algae but is metals precipitating out of solution at least partly due to the increasing pH since adding a hypochlorite source of chlorine increases pH upon addition.
Increasing the PH further makes the problem worse. Adding acid to reduce the pH would have at least put some of the metal back into solution after which point you could add a metal sequestrant to prevent it coming out again.
Copper-based algaecides would add copper to the pool while Trichlor pucks in the skimmer would make your pool extremely acidic. Zero TA translates to your pool pH being below 4.5 which is quite low. So perhaps copper from the heat exchanger got dissolved.
Will Chlorine Change my Pool Color from Green to Normal Color?
If the issue is algae. Then yeah, it will but if its not, it won’t. Chlorine cannot clear copper.