Thanks for the info and advise.A few observations here. First, I never suggest one use 4 ppm of ammonia for cycling. 2 ppm is more than sufficient. Perhaps 3 ppm if it is a tank with a p[H approaching 8 or above.
Nitrobacter is not needed in an aquarium. This bacteria is found in waste water treatment and other high nitrite situations. If you test an established tank, you will find little or no nitrobacter. Also, the strains of nitrosomonas are not the same in fresh and salt water. So much for what I might say about MicrobeLift,
You are correct that the bacteria reproduce mor rapidly in warmer water, the ammonia bacteria like a bit highr temp than the nirtie ones. I would suggest mid 80s F as a good place to be. You can always adjust the tank temp down when the cycle completes.
The nitrifying bacteria basically need a few things to thrive: Oxygen, Inorganic carbon, iron and a few trace elements plus the ammonia and/or nitrite they convert. Fir the hobbyist this means insuring there is enough gas exchange in the tank as well as a decent KH. KH is often called carbonate hardness and the bacteria can use this to satisfy their carbon requirement. This means when cycling one needs to check the KH since it can drop. if it does, the cycle can stall or fail to start.
The process of cycling a tank requires some amount of the needed bacteria be present. How much there may be can vary from tank to tank. With a proper bacterial starter product the cycle is well accelerated since both the need bacteria are present. As soon as any ammonia is converted the nitrite bacteria are already and waiting to handle it. Without the starter, one needs to build up the nitrospira population from scratch which is a slow process.
The final consideration when working with a bacterial starter is to realize the bacteria are live. The nitrifiers do not form spores when facing hard times. They are pretty hardy and will go dormant when the needed oxygen or the ammonia and nitrite is no longer available. So what can kill these bacteria? The most common thing when dealing with bottled nitrifying bacteria is temperature. If they are frozen, they die. If they are too warm, much over 100F for any length of time, they die. So how these products are stored and shipped can matter. This is true of all the potential products which contain the proper living bacteria.
I always suggest that one choose Dr. Tim's One and only or Tetra Safe Start as being the best options in this area. They are essentially the same product as the patent is shared by the two companies. Dr. Timothy Hovanec is the man who did the pioneering research into identifying the bacteria present in tanks. For those scientifically inclined"
Paper showing the expected bacteria in tanks was not there:
Paper identifying the nitrite converting bacteria:
Paper identifying the ammonia converting bacteria:
Since Dr. Hovanec et al wrote the above papers it has been discovered that there are ammonia oxidizing Archaea involved and that some strains of nitrospira can process ammonia directly to nitrate.