Thanks for the nice comments!
It's not that clean.. I just avoid shooting pics of the algae ;-)
There's an in-depth thread about ozone in the SPS forum... do a search for it.... in short, ozone is a O3, a powerful oxidizer that you can inject into your skimmer to increase production, and oxidise waste. It also makes the water crystal clear, and raises the ORP, or "reactivity", if you like, of the water.