Renantheras virus/sunken dark spots - help!

[mpiggy]

Purchased this Renantheras about 2 months ago while it was going out of bloom (see picture). I was recommended to grow the Renantheras similar to a vanda.

It is kept in a warm room w/direct sun in a south facing room in Maryland. I had repotted it in a vase half way filled with water to encourage humidity around the roots. The plant itself is planted in a pot filled with lava rock that sits in the mouth of a 1/3 filled vase. The vase water does not touch the roots or the pot. However, I can see humidity droplets inside the glass of the vase. I water every other day with very weak fertilization. This technique has worked well a vanda.

I returned home after a 4 day work trip this afternoon and was alarmed when I saw the leaves (see pictures). The room temperature may have dipped down to 50 degrees. I know I need to intervene immediately - but not sure what I should do.

1) I plan to remove the diseased leaves and spray with physan.

2) Should I also repot in coarse orchid mix? And try to grow it more similar to my thriving phalenopsis?

3) What roots should I be focusing on? Those in the pot or those growing a foot above the plant base?

This is my first Renantheras. I have about 10 phalenopsis and 5 catleyas that grow/bloom fine for me. I keep a vanda is a similar vase set-up. This is my first major case of a virus and I'm alarmed!!

Please advise.

Thanks!!

[CR7cristiano]

Just spray with phyton 27 or some neem oil to control the situation. I find that when you leave this type of orchid indoors in a central air situation the air tends to be too dry and when you supply moisture in this way it can get too damp for extended periods, and renanthera don't particularly like this. As winter comes along, I would recommend a potted setup with a growing light. As winter is a reality for you, I think that to keep your new plant happy you may have to go with one such setup in a nice course bark and perlite mix and make use of a humidity tray filled with water and stones so your pot doesn't have to rest in the water that you set twice a month outside of your weekly watering and fertilizing every other watering.
You should be fine, so long as you address the situation asap.