First time with Disa, how much should it be fertilised

[RosieC]

Picked up a Disa to try at a show yesterday and I asked the vendor lots of questions but forgot to ask how much it likes being fertilised.

For most of my orchids I use Rain Mix (aka MSU) at a weak concentration with every watering.

Would this be happy with something similar, does it like more or less at different times of year, should it be stronger/weaker?