Sorry should have made it clearer not for light . I don't do any of the gut instinct things.ie no smoking vaping blah blah. Up until recently these where only available or sold by to my knowledge an American company. But are know available in the uk ( as its the holidays) I haven't been able to get any feed back from the company) I was just curious as I have a turtle in the same room as My cham and even with frequent water changes can sometimes smell . Obviously I can deal with that over any endangerment of the animals.