I decided to nuke the tanks with hydrogen peroxide... but to answer your q's, I did not over stock, i just didnt quarantine. I have (had) two established 55g's and one established 37g tank. I added an appropriate amount to each tank and had an outbreak of ich in one 55 g and the 37 g. The other 55 g didnt outbreak, but since all fish came from same place I returned. Upon walking in the store today, I saw that all of the same fish I purchased had ich there as well. Coincidence?I think not. I was just curious if I could or should save the bio media to restart my tanks. Unfortunately, I rage nuked all my tanks so I have to start over. The store manager told me that I should have saved it. Oh well, to live is to learn.