An ozone injector device comprising a housing, a corona tube disposed within the housing and configured to generate ozone, a check-valve having a first end removably coupled to the water passageway and having a valve seat and a second end configured to receive ozone, the second end having a cavity with a movable float contained therein, an ozone inlet fitting removably coupled to the second end of the check-valve, the ozone inlet being in fluid communication with the corona tube via a corona discharge tube such that ozone entering the water passageway through the ozone inlet must pass through the check valve, and a spring-loaded clearing piston positioned to move into and out of the water passageway directly opposite the ozone inlet, the clearing piston being biased upwards, towards to the ozone inlet, and configured to prevent flow of ozone into the water passageway.