Wow what a great project, great blend of high tech and low tech, with the soil.
Firstly, I hope you had a lift, I know how sapping it can be lifting bags of compost etc. upstairs, I used to have a balcony set up myself.
Love the robot.
I'm surprised you didn't go for a hydroponic, or even an aquaponic system rather than soil, it would seem a more natural fit for the tech.?
Yes, I had a lift but it still involved getting 150 bags of soil from the street, into the building, into and out of the lift, down the corridor, into our apartment, through it and out onto our terrace.
The farmbot is designed for a soil based system and it also needs to be a nice looking feature on our terrace. I already have a drop irrigation system with fertizer from our Home Biogas system providing liquid fertilizer.