Get some test strips for it and make sure it is within safe levels. Ozone can poison you so care should be taken. Also ozone only has a half life of 30 minutes, so in plain english an ozone molecule will only last for thirty minutes (give or take) before it breaks down and becomes useless for your purposes. So you will need to run it at least every thirty mintues. Depending on your sq footage you may only need to run it for 5-10 minutes to achieve the .04 to .05 level that has been declared safe for humans. On the other hand the higher the concentration the more toxic it becomes to mold and fungus and what not so higher levels are ok as long as YOU aren't being exposed to them. Ozone also naturally occurs at much higher levels than the .04 put forward by health Canada as the safety standard. In populated urban centers ozone can reach levels of 0.12.
Experiment and be safe, buy a respirator if you can afford one or at least turn it off for 45 minutes before entering the room its in.