Alright, I've started to see a bit of a comeback... finished the research on nute burn / nute lockup, pH, etc... so I've got it all right now.
The back right one was cut from 6th node to 2nd node, therefore producing 4 colas. "Uncle Bens Topping Tech".
The back left one was cut from 7th node to 4th node, just for curiosity.
The front one was cut from 10th node to 2nd node, for an even possible 6 colas.
They've started to produce more leaves on the cola shoots, but they're VERY lime green in color and growing slowly, so I've determined it's nutrient def, so I've added a 1/4tsp to the res after checking pH was at 5.8 - This is only half the recommended amount.
Below are pictures, water change not due tomorrow, because of the much larger reservoir.


