Haha, yeah, the rocks are black. I saw them turn solid black briefly before the water darkened and cloaked them in a veil of secrecy. And no, it's not a biofilm on the glass, the glass is actually pretty clean, the water really is that dark. A skimmer just got bumped up to the top of the priority list, I'll try aerating as well. Oh well, in a few months when the tank is looking good I'll have pictures to post and look back on
