Oh no! My phal roots!!

[sii]

Well I had my 2 bigger orchids repotted in sequoia bark and I placed them on the side of my bathtub because that's the only eastern window in my house. I hadn't watered them much so I decided to take a look at the roots to see if things were progressing with the new medium even though they are in clear pots. I found the tips of some of the roots were moldy?!?! So I took them both out of their pot and the rest of the roots were in very poor shape. The roots that were once green, now are black and some were brown. I did my clean up, aired out the medium (which wasn't very damp) washed the bottom of the orchids and let it air dry before I repotted it and returned it to my office (southern window) What did I do wrong? If I leave it by my southern window, how close should it be? I could really use a wish right now.....