Dying Miltoniopsis Help

[alexharisiadis]

As I alluded to in my introductory post, I am need of advice for a dying milt.

I have never had any luck with this milt ever since I acquired it two years ago. When I bought it, it was already in spike. After the bloom cycle finished, the plant seemingly went dormant and, for a while, was doing okay putting up new leaves, etc.

All these new leaves were pleated, however. After a while, when I moved it to a side table a few feet away from a southern exposure, any new leaves the plant was putting up were looking good and relatively devoid of pleats. I think it helped that I was trying to keep it as hydrated as possible.

Then, all of a sudden, all of the plant's leaves started to die off and the guy essentially went bald. I decided to repot the plant in some fresh medium and also trimmed off a lot of dead roots during that process.

Well, that was a bad idea because as I've noted, any remaining leaves and bulbs have started dying. The bulbs have started to wither and turn a copper brown, and there is now only one sad looking leave that is rapidly dying. You can see the current state of things in the attached photos.

Here are the main facts:

Exposure: Western
Potting Medium: RepotMe's potting mix for oncidium (lots of coconut husk, pebbles, etc.) and some sphagnum mixed in for moisture retention
Pot: A cool pot acquired from the Orchid Gallery on Etsy
Humidity: Not high enough, admittedly
Fertilizer: RepotMe's MSU fertilizer, well-diluted, 3 weeks on, 1 week off
Water: Tap water (methinks this could be the problem)

A friend suggested that I try reverse osmosis or distilled water daily in the hopes of reviving the plant. Given my luck, however, I think it may be too late. Nevertheless, I'll leave it to the hivemind to help!