Ditch the transformers, all you need are a couple of *7805 voltage regulators (5V) for powering the single colored leds, and a *7812 voltage reg (12V) for powering the arduino and a cooling fan. Here's a link to the ones I use all the time- they're rated for 1.5 amps ( more power than you'd ever need)
5 Volt - http://search.digikey.com/us/en/prod...6-1-ND/1204660
225 Gal, Glass "Reef Ready" w/ twin Iwaki Pumps & 2 Ocean Clear inline filters. Custom 320 watt LED Lighting system utilizing a 6' Maker's Heat Sink, 12 BridgeLux Vero 18's,3 purpose built 5 channel A6211 Led driver/Controllers,iAqua Aquarium Controller
, and a 20lb CO2 system w/ Milwaukee Ph Controller.