At VapeUniverse, we strongly advise not to put water in a vape pen. Vape pens are designed to vaporize e-liquids that contain specific ingredients like propylene glycol, vegetable glycerin, flavorings, and sometimes nicotine. Water doesn’t vaporize in the same way and could damage the device, cause it to malfunction, or even lead to burns if heated incorrectly. For a safe and enjoyable experience, it’s important to only use e-liquids specifically designed for your vape pen. Always follow the manufacturer’s recommendations to ensure proper use and longevity of your device.