Hey Terry,
I can draw a diagram on paper and scan it if you like, with CAD or Fritzing i'm not so good

I'm using the Sainsmart 3.2" TFT touch screen. Ordered it from Ebay. It uses the UTFT and ITDB02_Touch library from
Henning KarlsenFor the pH I'm using a Phidgets 1130 pH/ORP module, this has got a BNC connector where I can connect the pH probe (also ordered from Ebay) to. The
pH probe itself is the cheapest thing I could find, because the primary idea behind this project was to make a cheap pH controller which wouldn't break my wallet

I must say that the accuracy of the probe is more then enough for hydroponics use. It has got an accuracy of 0.02, which isn't to bad at all. After that was complete the implementation of all the other sensors was a piece of cake

All other hardware and libraries are mentioned in de code, if you want to know...