According to Shaklee, by the time young Americans are 18 years old, they've spent seven of those 18 years with the TV on. Watching an hour of television a night might be a very nice supplement to the day, but having it on for seven or eight hours is not. Marathon TV watching is especially harmful to preschoolers who are still learning to speak, Shaklee says. The background noise makes it difficult for them to hear how the words should sound. It interferes with their auditory reception.
Television watching also exposes children to high doses of violence and materialism.
You're setting yourself up for family conflict. She recommends developing alternatives before you flip off that switch. Then, be firm, even if the children object. It's your job to set the boundaries.