The Arduino specs say 6 - 20 volts as the limits for input with 7 - 12 volts recommended. I have a 12V power supply that will feed the Arduino, three 12V fans and, with an LM317 voltage regulator, the 10V for the PWM signal to the Meanwells (via a transistor controlled by the PWM out of the Arduino) so that is all figured out. Just have to build that part

. The main thing I need to figure out will be programming the Arduino as I'm not a programmer.
I have followed many threads on LEDs on reef central and nano-reef and have built a basic array for my pico tank already (6 LEDs and one dimming buckpuck). The array itself is all wired and works fine without dimming right now. Now it's on to assembly in the housing and then building and programming the controller.