I'll take a quick stab at that one....
Algea do not grow from sunlight alone...they grow from nutrients in the water, in combination with a light source. If you keep a relatively nutrient poor system, you will not have algea problems. That being said...even the natural reefs would be overgrown with algea if it weren't for all of the grazing fish and inverts that keep it clean. So, a good algea cleaning crew is also a nessecity in any SW reef system....especially one using natural sunlight. Sunlight will cause more algfea than normal to grow if the nutrients are there to feed them due to the higher intensity and "yellower" spectrum that natural sunlight produces. Captive reef systems have shifted to "bluer" lighting to mimic the look of the reef at depth...the "bluer" lights are less useable by nuisance algeas, and more useable by the symbiotic zooxanthalee in the coral's tissue.
Again, grazers are a KEY part of any reef setup, and you'll see that redox has no shortage of them in his system.