Thanks everybody for the suggestions.

Stinky, thanks for the tip on spraying. I just started spraying about 4 days ago in an effort to raise humidity (in case that was the cause of the shriveling leaves). I'll continue but add in the nutes as you suggest. Since I have no place to get it locally, I ordered some CalMag Plus online, but that won't get here until probably Thursday or Friday. Until then, I will go back to the tap water and just stomp the Ph down the best I can. The PPM of my tap water is about 120, so it's not too-too terrible in that regard -- just the Ph is bad. The water temp is running about 65 right now. Even with the extreme cold of the past couple of days it never got below 62. The high temp in the closet averages about 75, and the lights are about 8 inches away so I doubt there's any heat stress involved.

This thing will probably go hermie on me, won't it.

Thanks again, everybody. I'll update as things progress.