Marconis and I have talked about this quite a bit in the chatroom. I can also answer 7s question about the nitrAte levels.
Remember, mine did this same exact thing. My NitrIte was stuck at 1.5 for 11 days. During that time, my nitrAte level always consistently read 6ppm. It never waivered at all.
After 11 days, I decided to skip dosing ammonia, and the next day my nitrIte level was down to 0.5ppm and my nitrAte level all of a sudden read 120ppm. This is why Nick is stating that his nitrAte level is unreadable or inaccurate, based on the fact it's doing the same thing that mine did, and there's no way 114ppm of nitrAte was developed over night in my case.
I am convinced in my mind that other factors are at work here. Something is in the tank that is corrupting the NO2 and NO3 levels. It may very well be that his cycle is long since completed, and there's some other phenomena that's causing whacked out readings when we test for NO2 and NO3.
Now here's the kicker I just thought of just now. When I was starting to suspect my test kit was potentially erroring, I took some water to the LFS to have them test it. They tested with the API kit and got the same readings. However, they happened to have an open bottle of nitrAte test strips laying around, so we dipped one of those. The API was reading 5-6ppm on the nitrAte (both my test and the LFS test), but the strips showed a reading of 60. I'm wishing now I would've had them dip a nitrIte strip to see what that read. While I know the strips aren't as accurate as the chemical test - in this instance it's gives a data point that shows a major inconsistency here. At the time I blew off this piece of data believing that the test strip reading was bogus. I'm not convinced of that anymore.
So, I believe that something is causing the reagents in the test kits to react when they shouldn't based on all this info, and the fact that it is just too bizarre that Nick's cycle is following the footsteps of mine almost identically up until when he added biospira last night. The past several days Nick has skipped at least 2 days of dosing. So, in any 24 hour period, he either starts with 2ppm of ammonia, and ends up with 1.5ppm of nitrIte, or he starts with 0ppm ammonia, and ends up with 1.5ppm nitrIte. This doesn't make any sense assuming the nitrIte levels to be accurate. If 2ppm ammonia changes over to 2ppm nitrIte - then he's converting 2ppm nitrIte in that 24 hour period. So if he starts with 0ppm ammonia, he should still be converting 2ppm nitrIte in that period, which is not evident based on the nitrIte readings.
With my cycle, when I did finally skip dosing, things kicked over - however I believe that to be potentially purely coincidental that it happened at that time, and think that if I had dosed ammonia that day, the same thing would've possibly happened with the nitrIte level.
What is driving me nuts, especially being an engineer, is that I cannot figure out what it could be. I don't necessarily believe that whatever is corrupting things (if that's what is happening) to be harmful to the bacteria or even to fish, it's just causing a chemical reaction with some ingredient in the NO2 test kit and possibly inhibiting something in the NO3 test kit.
And like Sparky said - if he really did have 1.5ppm nitrIte present, and changed out almost all of the water with tap water which has tested at 0ppm nitrIte, there's no possible way that he could've gotten 1.5 again after the PWC. The nitrIte would have gone away, or at the very least been diluted down to almost nothing. That again is what's leading me to believe there's something else present that's simply reacting with the chemical reagent other than actual nitrIte.
Just some thoughts of mine...
Stupid Marconis 
