2 cubes and 2 pinches. I also have several different macroalgae in my display tank. I supplement with iron.

The blue/white LED is an experiment that has me building a "tunable" LED array that covers all of the peak wavelengths of marine algae. There are 5 individually adjustable arrays of three 3w LEDs, 440 & 460nm blues, 6500k white, and 620 & 660nm reds. I want to see how each wavelength impacts the algae variety and growth. I'll post some pics this weekend.