Help! Orchid Going Downhill

[cherrypuff]

Hi all! My grocery store phalaenopsis has been going downhill since I bought it.

Today, I went out to buy another orchid (Orchid 2) to add to my collection, and couldn't help but notice how firm its leaves were, compared to the one I bought a week ago (Orchid 1).

Here are pictures of the phal I bought today (Orchid 2):

Orchid 2 - Album on Imgur
Orchid 2 (Leaves) - Album on Imgur

Versus the one I bought last week (Orchid 1):

Orchid 1 - Album on Imgur
Orchid 1 (Leaves) - Album on Imgur

I'm not sure why the leaves on Orchid 1 have become so limp and droopy and dark. They definitely weren't like this when I bought it last week...

Here are the conditions in which I grew Orchid 1:

Light Source: SANSI 32W LED grow bulb
PPFD: 285 umol/s/m2
Photoperiod: 18 hours
DLI: 18.48 mol
Temperature: 85° F (29.4° C) days; 70° F (21.1° C) nights
Humidity: 40-50%

What could be the cause of this? I haven't repotted Orchid 1 since it's still in bloom and the root system looks very healthy. I've also added a bit of sphagnum moss to cover the top roots, and waited until the roots looked silvery before watering it with bottled water. I let it drain completely before putting it back in its decorative pot.

I really love this orchid, and don't want things to continue going downhill from here. Thank you!