Hi Esther,
I and many others consider the “Nellys” to be tricky to sustain long-term. Referring to the excellent You Tube channel of “MissOrchidGirl” a grower with a large diverse and superbly healthy orchid collection she has ranked the Nelly as her Number 1 most difficult orchid! So Esther you have to be congratulated. Obviously the specific growing conditions you provide are key! So keep on doing what you are doing!