sick royal critical.

Looking for any advise. Royal queen critical 22nd day of flowering. 300w cfl. 27 degrees temp. Using bio biz bloom.
Over the last week or so only the top leaves seem to be curling and looking a bit wilted. The lower plant life seems fine. Buds seem to be filling out nicely. Am I under/over watering or does this look like some deficiency. I hope the pics show her ok. Please help guys.

She looks thirsty.

thanks for the fast reply, it would make sense as its starting at the top of the plant first.

The leaf curling at the top happens when the light is above the top of the plant.

It looks healthy but could use more light.