There are many available products that claim to contain cultures of the bacteria needed for an established aquarium. In my experience, most of these products do nothing more than shorten the process by a few days, if even that. Bio-Spira, by Marineland, is the only "bacteria in a bottle" that I had really noticeable results using. I definitely recommend it for speeding up the process if it's available near you. Filter media from an established tank, gravel from a tank with an under gravel filter, or even the brown nastiness from a filter cartridge or sponge rinsed in aquarium water will all aid in jumpstarting those bacteria colonies. "Borrowed" media can be placed in a filter mesh bag (no nylons, they can have bacterial agents in them), then added to your new aquarium. Doing this can shorten your waiting period to a matter of days, rather than weeks for the cycling process to complete. (Yes, I know the idea of messing up your beautiful new aquarium is hard to take, but it DOES do wonders!) I personally tend to be into instant gratification so this part of the process is very important!