VerticalFarm is a microcontroller project. It's features are pH monitoring, balancing, and reporting.
MIT
=$105 SparkFun= https://www.sparkfun.com/products/10972
=$130 Atlas Scientific= http://www.atlas-scientific.com/product_pages/kits/ph-kit.html
Code Sample http://atlas-scientific.com/_files/code/pi_sample_code.pdf And I helped!