Tillandsias grow differently than most other house plants - they pull nutrients in from the water and they bask in the sunlight (bright, indirect, not intense direct light) and DO NOT need to be planted in soil! 

1. If you are growing them indoors and the air is dry, you will need (at minimum) to submerge the plant in water for 2-3 hours about every two weeks. 
2. In a shaded-house or less heated home, you can mist them until they're dripping once or twice a week in summer, once a month in cooler weather.
3. Once the soaking is over, allow them to dry upside-down in a dish rock or on a towel so that any water that collected in the nooks and crannies can drain.