yeah like i said they do create ozone. WHich is poisinous. Proper ventalations key. It turns the smelliest air into after rain smell. they blow carbon filters away. no way carbon can keep up with a ozone generator. do your research. its not as simple as plug and play. but its what the big dogs use. they do leave a distinct smell. and once you smell them you will alway know when you smell one. anouther reason venting is so important. but vented outside,,,, near impossible to know theres a large grow op just feet away. good luck man