Thanks for the question. I initially started measuring the soil capacitance with the moisture sensors and found that I was spending too much time fiddling with individual plants and couldn't control their moisture independently (not enough analog inputs on one arduino). I then decided to move to Blumats because of the simplicity of automation and calibration. At the end of the day the point of this project is to have a garden that grows actual food with minimal human interaction. The old code for sensing is still in the program providing valuable data about relative humidity and soil capacitance. The arduino will be used as a sort of emergency shutoff valve if the blumats go crazy.

Kadir,
I had considered the use of some pH monitoring but wasn't quite sure how to implement a reliable automated solution for 12 or more individual plants. I'm thinking my next project will be a home made hydroponics system that incorporates pH control, ppm/nutrients and aeration from a single controller.

Snaresman,
I personally learned the little bit of c++ I know from here.
https://www.codecademy.com/learn/learn-c-plus-plus
You can make a free account and get the pro subscription for week long trial which should be long enough to complete the module. Then once you get the basics you just search for the libraries of the hardware you are connecting to Arduino and watch youtube tutorials of how to use the libraries.