What's happening to my Phal? Others have the same ailment.

What's happening to my Phal? Others have the same ailment.
It looks like sunburn to me. Is it in an area of really bright sunlight?
Think Cathy's right

I grow them under 40" florescent lights in winter, outdoors in the shade in summer (Maryland)
Do you think you got it too close to the fixture?
Ditto to cathy, looks like sunburn.
Alex