We have to drain our swimming pool that has algae, will this harm our Zoila grass?
These are the guidelines that I was able to find.
These are only guidelines and I cannot say for sure that you would not have damage to the grass.
You will need to test the water. The chlorine level should be no higher then 0.1ppm.
PH should be in the neutral range 6.5 to 7.8.
I also should point out that the research showed that most cities have strict guidelines on discharging pool water in the sewer system and you may need to notify the city.