UltraPure Ozone Test KitUltraPure Ozone Test Kit Many hot tub owners often overlook the functioning and purpose of the Ozone generator. Until recently, there has not been a method to determine if is time to renew or replace your ozone generator. Even if it appears to be running your ozone generator may not be producing sufficient ozone or any at all. The UltraPure Ozone Test Kit indicates if there is ozone present in the output stream from the ozone generator. These kits do