Black Spongy Hairy Encrusting Bacteria
 

While the title sounds like a horror movie, this is actually the pest in my tank.

<iframe width="560" height="315" src="https://www.youtube.com/embed/hy7lEqqqLQU" frameborder="0" allowfullscreen></iframe>

With the help of some capable professionals on this site, we have video proof that it is a collection of bacteria including cyano and several others:

http://www.reefcentral.com/forums/sh...+algae&page=23

Over the last couple of weeks, I've used the opportunity that I'm tearing down the tank in a few weeks to try more aggressive treatments.