Finished up the wiring. Tested it out today by turning a fan on and off. Seems to work out pretty solid. I already had this system monitoring the PH, and temperature, but now with a bit of programming, I can get it controlling the CO2 relay, air pump, and lights. All of which will be timed off the real time clock with battery backup. That's the green module mounted on top of the arduino mega 2560.
I haven't figured out what I'm doing with the other 5 plugs. I just need to buy more gear I guess.