Necrotic spots rapidly spreading through out this vanda tessellata

[Russell 99]

Originally Posted by Roberta

Did it get cold? If that's the case, you could watch and see if new leaves are OK in a warmer place (and perhaps the black spots will dry up), but do isolate it from other plants.

Yes it did get quite cold since I moved to the mountainous area(1300masl) of Sri Lanka
Temperature dropped from 28-30 to 23-18-15 Celsius.