hmmm, from my experience ive had really good success with just Cycle. im actually suprised everyone doesnt have better experiences with bottled bacteria, also ive used microb lift cause i use it for my outdoor pond in summer and it keeps the algae in check really really good, my pond would be a giant slime pit if it wasnt for the microb lift, it contains methane supposedlly to put the bacteria in a suspended animation until you add it to water, thats just what the bottle says so. back to the tank though, i just recently got a new tank, new filter. put cycle in it and added fish the same day, three large cichlids and two bichirs and in the two weeks after i did it i got no mesurable readings of ammonia or nitrite, and now i get nitrate readings, so, the cycle pretty much completed as soon as i did it. I know some wont believe me, but i relaly do have a 75 gallon full of healthy cichlids that were put in a new tank on day one, just using cycle, since then its been about two months, still all going good, so, in my opinion, descenting from everyone else here apparentlly, I love the stuff, works great for me, i always have it on hand