Just keep testing diligently and changing the water as necessary.
It is really very simple. Basically, you need two basic types of bacteria in order for the tank to undergo the nitrogen cycle. One type of bacteria eats ammonia--it needs ammonia, heat, water, and oxygen to thrive. This bacteria excretes nitrite as waste after it consumes the ammonia as food. Another bacteria eats nitrite, and it also needs nitrite, heat, water, and oxygen to thrive. This bacteria excretes nitrate as waste after it consumes the nitrite as food. Luckily, even though there are no bacteria that consume nitrate, it is much less dangerous than ammonia or nitrite and can be tolerated at much higher levels. This greatly minimizes the need for water changes.
In order to cultivate a colony of these types of bacteria you have to give it what it needs. Your job is to nurture the minuscule amount of bacteria floating dormant in the water until it is a full blown colony, capable of instantly converting ammonia into nitrite and nitrite into nitrate the moment it becomes available. Remember that with no food, it will starve; with no heat it will not grow; without water it will dry out; without oxygen it will suffocate. The bacteria must have all of these things all the time.
It is easiest to nurture bacteria when you do the fishless method, because you can crank up the heat, add lots of aeration, and pour pure ammonia straight into the water without worrying about the consequences that would cause the fish. However, since you have elected to do the fishless option, you will just have to test diligently until the colony is large enough to immediately convert all ammonia and nitrite into nitrate. So when your ammonia level and nitrite level both consistently read 0, and you are left with nitrate only, your cycle is completed.
Last edited by Adastra; 12-20-2010 at 04:55 PM.