I was just looking into this as I'm having a little bit of trouble too... what kind of temps are you seeing?

I only get up to about 65-75 ambient during the day... under the lights it's probably 75 or so (I hope). At night I'll dip down between 55-60. I think 56F is the lowest I've seen. Sounds like that's probably not a problem though as I'm guessing you guys are having lower temps and doing alright?

I thought I noticed one of my Sativa strains' fan leaf stems redden up pretty much overnight recently...