Well, I should say that I've only had these since February. I got them as a gift from Brett Moloney (thanks!) via Oii Leng Sun Orchids. I grew the very similar species C. pictus for around 4 years before losing them.
They cannot tolerate dry air or soil. I've grown them in a mix of leaf humus (no fertilizer in it!), kanuma and a little sand. They are grown essentially in terrarium conditions. The best thing is to have no seasonal variation in temperature, light or moisture. Just keep them moist, warm and in bright shade 24/7 year round. They go dormant when they want, and reappear when they want (hopefully!). They will grow best using rainwater, RO or distilled. I don't fertilize at all, not even organic, though you probably can. I'm too afraid to burn them. BTW, the moss in the pic is just for show, I grow them in bare soil to prevent them from being overwhelmed.
Maybe give them a bit more light? Phalaneopsis level should be fine.