There is no reason to "manually" cycle a small tank
I am thinking out loud here, for the benefit of people who have never experienced this. For tanks less than, say, 10-15 gallons, I cannot think of any reason to cycle a tank the old-fashioned way. Now that research has shown the correct bacteria for nitrification, the cycling products on the market are fantastic. The ones I've used are Tetra's Safe Start and Nite Out II.
For any small tank, my methodology is:
1) Fill with dechlorinated water.
2) Run the filter for a day or so with activated carbon. Probably not necessary, but I am a little paranoid.
3) Remove carbon, dose ammonia to ~1.5 ppm. (keep doing this once a day until fish are added)
4) Add nitrifying bacteria.
5) Drink a beer.
Measured in time since adding ammonia, my results are usually:
24 hours - Beer has worn off. Ammonia zero or close. Nitrite 0.25-0.50 ppm
48-72 hours - Ammonia zero, nitrite zero.
Congratulations, the tank is cycled. I am astounded how well the products work. For large tanks, the cost may be prohibitive. Also, if the bacteria in a bottle was not kept from being too hot or freezing during shipping, you could get a dud.
For small tanks, I usually add a dose from two bottles, one from Safe Start and one from Nite Out II, just in case. Seems to work pretty much every time.
I was wondering if anyone else goes this route and if they have been as successful as myself.
I grow plants underwater.