This is the only time I've heard of this, and it makes the most sense to me!!!! I have a tank that has rock that I would call somewhat live, but it's not the same live rock as in my other reef tanks. This particular tank has a problem with collecting gunk that doesn't seem to break down. In my other tanks, I get detritus somewhat, but not gunk. So this tank I'm referring to that collects gunk has a cyano problem. The cyano always binds to the gunk. No matter how much flow or how much phosphate absorbing material I use, I still get cyano. If what you say about the bacterial balance is true, I think my issue with this tank might be that the biofilter is not breaking this gunk down enough to that my skimmer and other filters can pull out the crap, instead the cyano is feeding directly on it. Does that sound right? I think I'm going forward with Microb-Lift.