Grammatophyllum elegans Leaves turning yellow

[mjf45322]

Help, I need to know what I am doing wrong with this species plant. I got one from Hawaii 3 weeks ago along with 2 different clones of Gram. Scriptum. The Elegans new growth rotted off and the growth/bulb next to it has its leaves all turning yellow. I got another plant from the same dealer and since it was out growing its pot I moved it into another 12" pot big enough for 2 more years growth . I noticed today that the tip of one of its leaves is yellowing.
I grow in a greenhouse with 65% humidity. I have the plants in a area wher they get max. light with day time temps of 90F and night temps of 55F.
I water 3 times a week normally overhead, but have the plant where it will not get soaked. It gets a light mist from my fogger when its on.
The Gram Scriptums are in smaller pots and get soaked when they are watered and they are happy. Should I treat the Elegans the same. Should I try growing it in a smaller pot.
The grower in Hawaii grew it in a potting soil with a little bark. I was afraid in my climate of root rot so I repotted it into a med. bark/perilite/characoal mix.
Should I allow it to get soaked when it is watered eventhough its in a huge pot with good drainage.
Thanks,
Mike

[stonedragonfarms]

I do not grow this one, though from what I have read, it resents disturbance. Information on the web states that the plant is best grown under hot conditions in full sun, and that the plant should not be disturbed so that it will develop aerial roots (as it would in nature...) It may be that it is suffering due to the stress of repotting and too cool of night temps. Have you tried contacting the vendor to see what they recommend for cultural conditions?
Good luck!
Adam