Thanks everyone.
It's grown mounted (which is how I bought it) on some sort of fairly hard wood.
It's in the greenhouse getting whatever the outside temperature is during the summer (the door is always open in the summer) and it comes into the bathroom about this time of year until the spring. It gets reasonably bright light, at least bight for the here but we're not the brightest of countries
In the greenhouse I water daily, my fertiliser has changed over the time I've had it and it's done well whatever. This summer it was rain water mixed with Akerne's rain mix (aka MSU) at a pretty weak concentration 3-4 times a week, or plain rain water on the other waterings, now it's come inside and it's moved back to a different 20-10-20 fertiliser and is watered every 1-2 days. Last winter I used this at 125ppm nitrogen, this year I'm experimenting with half that.
I don't really worry about humidity it varies widely in the greenhouse and is quite low in the house, except when I have a bath as it's kept in the bathroom window.
Greenhouse light is quite bright, so is the light it gets in the bathroom. I've never measured it though and UK sunshine is not as bright as in some countries.