Spoiler alert: I wrote this blog post before realizing that the solenoid valve was normally open, when I expected it to be normally closed. The electronics were made specifically for one function and I cannot use them with a normally open valve. I will make new (and better!) control circuitry and create a new post about it. This post goes through everything I worked on to get the original design to where it is now. Look forward to Part 2 for details on the final working product.