Caroline,
There are three primary reasons an orchid won't bloom (besides simply being immature):
- Insufficient light
- Insufficient nutrition
- Improper nutrition (deficiencies or excessive nitrogen)
Unfortunately, the solution may not necessarily be "grow brighter and feed more", as things like temperature and watering frequency, to name but two, can affect nutrient uptake and metabolic rates.
I suggest you start a new thread with a clear description of your overall cultural parameters, and folks can help more.