If you cycled the rock for what is it, 72 days, ich is gone for sure. I'd bet most pathogens would be gone. I thought they could test for several pathogens. Ryan had some I thought.Okay, I watched their video, and it seems that their test may be able to isolate pathogens in the water column of an aquarium -- but it certainly wouldn't be able to detect encysted parasites or diseases of individual organisms like coral, and nothing in substrate. And I'd be more interested in finding out how my tanks' biota compares with natural reef environments, and not my peers' builds. Still, interesting!