Second case of mystery rot in Phalaenopsis. What am I doing wrong??

[Wade Coleman]

Hey everybody! So I have been growing orchids for about a year now and I own probably more than I should... hehe I’ve got phals, psychosis, dendrobium, epidendrum, oncidium, cattleya, and pahps, I’ve yet to lose any except for one Phalaenopsis that died of, what I think, was stem rot. I live in Hawaii and I don’t have A.C., so the windows are always open and there is always a nice breeze blowing through the room where my orchids are. Even if water were to accumulate in the leaves, I would think it would just evaporate so quickly it wouldn’t even be a problem. I noticed, however, that one of my phals has another dark patch in the middle of the stem just like my previous phal did before it lost all its leaves and died. When I water, I don’t pour on top of the plant, I pour it close to the roots so that water doesn’t accumulate in the crown or leaves or anything. I water the phals once or twice a week. The plant is growing a new leaf and the crown looks perfectly healthy. Already I see the leaves beginning to yellow and I don’t know what to do! I have quite a few other phals who are growing quite well right now, but this is the second case of this mystery rot and I don’t know how to prevent it or what’s causing it.