Hi everybody. I have some air plants that I keep inside glass 'terrariums' more or less...glass globes that have a mouth opening in the top. I soak my plants for a few hours, maybe once per week. Other than that I mist the plants inside their terrariums maybe every few days. But over time the plants seem to be becoming dessicated. I wonder if the watering is not enough, and I need to add some other 'substrate' or something to the globes, that will better help to retain moisture for the air plants? If so,what do you recommend I add...just a bit of soil/rocks at the bottom of each globe?

Tx!