How long does the crystal light have to stay in your hair for?

Crystal Light is not typically used for hair treatments; it's a flavored beverage mix and not intended for hair application. If you're referring to a specific hair product or treatment that involves crystals or similar ingredients, the duration can vary depending on the product's instructions. Generally, hair treatments should be left in for the time specified on the label, often ranging from a few minutes to several hours. Always follow the manufacturer's guidelines for the best results.