The co2 tank will be placed in the back right veg chaber on top of the boxed covering over the intakes (in the 1st pic below you can see the 6" duct piece i am using represent a shorter version of the co2 tank)... there is a round whole in the shelf to make room for it..

All electronics such as Sentinial CO2 controller/enviro with PPM, 2 Continuous Tri-meters for tds-ppm-temp, speed controllers, and temp/hydometer back-ups will be on that center shelf. I will have a webcam mounted inside the door so I can view the numbers from my computer.