One thing I think might possibly be of importance is that when I shine the light on the top of the water, there appears to be an extremely thin film or layer on the surface. It's kind of blueish. Any ideas? Maybe the water hasn't been filtering properly.

As for the conditions with the UV, I'm keeping the UV light on from the second I wake up [Weekdays, 7:00-8:00 AM, weekends 8-12 AM] and turning it more towards the tank when I return from school or at 3:00 on the weekends, turning it away at 6:00 PM, and shutting it off at 7:00-8:00.

Gnag's condition seemed a bit brighter when I found her basking yesterday, but it's the same brown once more today. Should I add more foliage?