I am using a number of 4' fixtures.. 2 T-12's w/ 5k bulbs and after having my plants in there for 2 weeks.. :^)
I put these guys up on the 9th of Nov.
Most noticeable difference is the PK in the next 2 pics.. over a 2 weeks period. The rest are getting over the shock of the trip from Ark.
I'm going end up moving the PK front (R) into the Big Banana room by the end of Winter..
To follow T-5 (2) and T-8 grow room and results as they present themselves. :^)