I don't let people smoke in my house anyway, so its not something I personally have to worry about. I just wanted to know if someone with better Google skills than me had found info related to the topic. So far I've gotten a post about the humane society and a link to some interesting info about the 'butts'.. Everything else has just been peoples $0.02, I don't mind opinions, but ultimately facts win out. If the facts say it won't harm the fish, then it shouldn't harm the fish. But if the facts say otherwise...