Real neat controller Billie!!
Great work on setting up your hydro setup. It's amazing how many plants you have squeezed into that space. It's great to see other projects and share the knowledge. Looks like there are a few people interested in controlling their own food production.
I just have one constructive feedback on the plant physiology side of things. If your able, you should really incorporate EC/CF control. Although pH controls nutrient uptake, nutrient availability is equally important. EC is a great tool for controlling, among others, such things as internode stretching, hardiness and taste. You can also control visual aspects such as cracking/splitting with EC control (particularly important with tomatoes). I think you'll have better control of plant size, especially during seasonal changes (i.e. winter vs summer ).
I'm making a similar controller using a mega connected to a raspberry pi with a 10 inch touch screen controlled by a website.
Anyway, that's my 2c worth, I look forward to your future releases!
Regards,
Damian