It is really hard to quantify the usefulness of Microbacter 7. I know there is a thread going on now about how we too often rely on anecdotes to come to conclusions in reefing and I would agree but they are not completely worthless.
I mainly use microbacter 7 to deal with cyano. After keeping tanks at home and the LFS for many years I would often use Chemiclean to treat cyano. It eliminates the cyano 95% of the time but sometimes I would treat and then the cyano would be back within a month. I do have a degree in ecology and my theory is that when the cyano is removed there is still an open niche in the ecosystem for a cyano like organism that scavenges dissolved nutrients from the water. If even the slightest amount of cyano survives it can grow back to fill this niche. I have started adding microbacter 7 after treating with Chemi Clean in an effort to replace the cyano with more desirable bacteria strains that aren't unsightly. It seems to work. I have not had cyano bounce back after doing this, though I have only tried this about 3 times.
