Yellowing Leaves on D. anosmum in the dead of summer

[cvelez]

So I was looking at my plants and noticed that the leaves at the base of my dendrobium anosmum are starting to yellow. As I understood it, the culture called for lots of light and lots of water. Currently have it in an indoor mini greenhouse, averaging 85% humidity, watering it everyday, next to a south facing window with a grow light coming on early in the morning, turning off during the day, and then on again when the sun starts to set, and air circulation coming from the bottom and circulating down... any ideas as to what's going?

The white balance on my cell phone apparently doesn't exist, so I'm not sure I captured the essence of what's going on. But one of the small leaves on one of the shoots fell off already...