Very nice job! I will have to upgrade soon as well. Did you ever consider adding a Tunze Wavebox Wavemaker instead of adding so many Tunze Streams? Just curious. I use Tunze Streams in my SPS systems, however, for my next upgrade I am considering adding a Wavebox instead of more Streams.
Also, did you have any trouble moving your Powder Blue Tang from the 120 to 180? I will have to do the same thing within the next year or two as well. Keep the pictures coming!