I cycled my 46 gallon community tank with Bio-Spira in nine days. Frankly, I thought my test kits were bad.
Ammonia never got above 1 ppm.
Nitrates never got above 1 ppm.
By day 9, my readings were 0/0/10, and stayed that way for about two months, until nitrates started rising (they hover around 20 now).
Eight weeks after starting, I had a nitrate spike of 0.5 ppm, that went away after two 25% water changes, three days apart.
That tank just passed the four-month mark.
Your mileage may vary (as with just about everything to do with aquaria, it seems
. But, I have to say that based on my experience, I'll try to use it the next time I start up a tank.