I'm using a mega board since I had one. I check my ph and tds with separate testers for now since it's what I have. I've been using a 10 seconds on and 15 minute off time using a terrible delay sketch and manually plugging the pump in for a an hour, after two weeks of this my reaper plant looks great. I'm reading several arduino books but still haven't learned how to have a timer with different start stop times and a counter for running my 1hr run after x amount of cycles.