A super hot week with moderate humidity during the night.
Interesting to compare all these plants to see how much genetics plays a roll in things. All plants are treated equally, but they're not all guaranteed to come out the same - with all sorts of shapes and sizes.
Poor plant 4 has been through hell to be honest - not sure how it's going to fare. It's had a steroid induced childhood pumped with the same nutrients I've been giving to the flowering plants.