Hi
Doubt if I can be of much help as I only grow this outside on a Myrtle tree. First this type of fern is a true epiphyte though I suspect it would also grow on rocks . Constant cycles of water ,drought. days apart During winter it almost gores dormant. Don't know if this lack of rain,cold weather or both. Have been told cool weather is not necessary but drought is . It needs to dry completely but for short periods. It grows and looks best during the rainy season.
These conditions are tough in a terrarium. So my advice would be to place in the upper reaches with no media.Maybe on cork?? Let it shrivel before watering again. Light levels might be a bit low,I usually see it in "dappled shade "
Don't know if it needs a dormant period but certainly what it gets in florida in the winter.
There not much help but like spanish moss it grows without any help from me. It some areas it is downright invasive. gary