Question
Hi,

I just bought a Phal Violacea 3 days ago and the flower is wiltering fast.  The petals are closing up.  I spray it with Captan solution when I bought it as it was wet.  It is mounted on a moss slab and hanging on a bright north-facing window.  I live in Singapore where humidity is around 80%.

Answer
I would check to be sure the roots are in good condition.  This may mean removing some of the moss so you can check the root mass.  Usually, your symptoms are the result of root rot from keeping the roots too wet and not having enough air movement.  After doing that, remove all rotten roots, or the plant from its mount if the rot is bad, reduce the light intensity by placing th plant in a more shaded location and reduce the moisture to a daily misting until a new, healthy root system is established.  You have the advantage of a humid environment and that may be all you need with little supplemental watering.  They like lots of air movement also especially if there is a lot of humidity.