Possible problems with cycling.

Question
Hello,

I'm currently doing a fish-in cycle with three fish in a 15 gallon aquarium. It has five live plants, two small fake plants and three terra cotta pots (which were cleaned prior to adding to the tank). Tank was seeded using filter media from an established tank and one plant also came from an established tank.  The gravel was used in another tank but had been dried out/stored for over a year and was thoroughly cleaned prior to being placed in my tank.  I'm using a liquid master test kit for my readings.

Day 1:  Ammonia: 0, Nitrite: 0, Nitrate 0, PH: 7.4 (fish added late in the evening, test done a little later).

Day 2: Ammonia: 0, Nitrite: 0, Nitrate 0, PH: 7.4

Day 3: No reading taken

Day 4:  Ammonia: 0, Nitrite: 0.1, Nitrate 0, PH: 7.4

Day 5: Ammonia: 0, Nitrite: 0.3, Nitrate 5ppm, PH: 7.4 (15% water change was preformed for the higher nitrite)

My question is: How am I getting a reading for Nitrite without a reading for ammonia? I did the test twice on day 5, as I was sure this could just not be correct and it was the same both times! Upon inspection, I discovered that my water condition neutralizes ammonia. Could this be that cause? Will my tank still cycle properly? As well, how am I getting a reading for nitrate on only day five of my cycle? Could the seeding really speed up the cycle this fast?

Sorry for SO many questions. This is my first experience with cycling and everything I'm experiencing seems to be going against everything I have read. The fish appear to be very happy. Still swimming and acting like they did the first day they were added to the tank.

Any help would be greatly appreciated.

Answer
Hi Michelle,
This is a late response, very late actually.  I was probably not the expert you asked because this question was sent to a category where the expert you asked could not answer the question for whatever reason.  But I am allowed to answer it if the other experts do not answer it.  For future references, if you decide to cycle another tank, here are the reasons for your previous tank cycle questions.    

First off, I'm glad you are using a liquid test kit rather than test strips! Test strips are very inaccurate.  You said you used an old filter media to seed your 15 gallon tank.  The reason why your ammonia levels never showed up is because your bacteria converted your ammonia into nitrite too fast to even see ammonia.  Also, the size of your tank also contributes to the fast cycling.  Seeding with used filter media speeds up the cycling process by already adding a handful of bacteria and you were able to cycle your tank within a week.  Whereas cycling a tank takes up to 4-6 weeks without seeding.  

If you see traces of Nitrate it means your tank is cycled or very close to being cycled.  On your day 5, you have a reading of Nitrite 0.3 and nitrate of 5.  This means your second set of bacteria, the nitrite-to-nitrate converting bacteria has not fully grown yet due to traces of nitrite readings but is very close to being done. Your tank should be completely cycled on day 8 or even day 7 from the rate of growth from your readings.  

When I cycled my tank from seeding it also took me about a week.  Seeding with live bacteria GREATLY speeds up the cycling process.  You know your tank is 100% cycled by getting 0ppm readings on both ammonia and nitrite with some readings of nitrate.  There are dry bacteria sold in cans at local fish stores such as the product called "cycle" but it is not as effective as seeding.  Remember though, that nitrate can only be removed by water changes.  There is no 3rd set of bacteria that breaks down nitrate.  Many aquarist fail to realize this which results in fish death in about 3months or more due to nitrate build up.  I keep my nitrate 10 and below only because I have some very sensitive inverts in my tank such as Crystal Red Shrimp.  But since you only have fish, they can tolerate up to 40-50ppm.  

Congratulations on fast cycling and I hope this info helps.
-Matt-