I've been having a similar problem in my last few crops.
This time one plant that was never thirsty has just shown it's ready to harvest WEEKS ahead of the other 3. 2 of the 3 remaining are also drinking less, but the last plant is just peachy!
Everything is the same. Even the dirt was mixed together before being split into the 4 pots. Tap water left to degas in 15L water bottles for days before use and all the water, and therefore nutrient mix, were shared. Plants were moved around half a dozen times (different lights). EVERYTHING was shared.
Is it possible this is a genetics issue? 4 seeds, 4 different sized plants. Granted, I'm still a noob with only 6 grows under my belt, but it's the only thing I can logic through as a likely cause.
