Yike's... amd I the only one left that try's to keep temps constant?
I mean I like purpling and bluing and red hues.. they are all very pretty... and at least until the very end, usually a sign your plant is uptaking nutrients a bit slower than it would like, and because of temp changes certain nutes are more prone to be almost nill in uptake at night (phosphorus is a biggie).
Now don't get me wrong.. I am not a scientist or even a botanist.. maybe my view of purpling is incorrect.. maybe it is relatively harmless... I like to consider it a communication tool.. like a cat crying when it is dinner time.