1982: The original dump-bucket style algae scrubber (works, but very hard to build, install, operate, and harvest)
2008: Waterfall style algae scrubber (works good but hard to build and install; must be removed to harvest)
2011: Upflow style scrubber (work goods, easier to build and install on the glass; must be removed to harvest)
2013: ??? (work great, all 3D growth, easy to build, and instant in-place harvesting without needing to remove anything or turn anything off).