pool water purification

[doublette]

I can't answer your ozone question but we use chlorine to maintain our 16' above ground. I fill it at the beginning of the season and maintain the chlorine level all summer. I don't have to drain and refill again for the summer. And when it comes time to drain it in the fall, I just let the chlorine dissipate and water the lawn and trees. Hasn't killed anything yet.
Debbie