It may have gotten dried out or even too much light. It is about 3-4 inches from two 15W GE CFL 6500 bulbs. The moss that is just an inch lower is still green.
It is starting to get stringy algae on it today. It isn't hair algae, more like a gelatinous thread.
I just got one oto, three ghost shrimp, and a couple mts so hopefully they will start eating my diatoms and this new algae back a bit until the tank settles in.