Hi Dorothy,
Just discovered your post re stenoglottis and you've probably had your questions answered by now. I've had a longifolia for about three years and it is doing very well with about 9 flower spikes at the moment. It is in a clay pot with a mix of fine bark, perlite, charcoal, bits of cut-up sphag and some white sand. I was told by the vendor that they like sand in the mix so did as I was told, even though it seems to wash out every time I water so I don't know how much is left in there! They like to be kept fairly moist when in active growth but are deciduous and need the dry rest. I mist occasionally if there is still growth showing. The number of growths seems to more than double each year and they are delightful when in flower! I hope you're enjoying yours.
Shirley