Yes, they live off the air but yes, they still need care...
Air plants get all of their nutrients from the air but they do still require an occasional watering. Here are some helpful tips to keep your air plant thriving.
Light: Bright, indirect light is best.
Watering: Once a week or so, soak plant in a bowl/cup of water for about 20-30 minutes. Remove from bath and shake upside down for a second or two. Allow to dry completely, upside down is best, for a few hours before placing plant back in its haven.
Temperature: They like to stay at a cozy 60-90 degrees.