TOPFIN takes care of both chlorine and chlorimines.......you don't need high temp to get bacteria to grow you should be fine 78-82.
I am not sure where you would get false readings from an additive..a dechlorinator only may itself be problematic if it is not designed to deal with chloramine.
I have seen false positive readings with those dechlorinators that work with chloramine..but it really is NOT a false positve..the ammonia test we commonly use test for total ammonia..(total ammonia = NH3+NH4)
the dechlorinators that work on chloramine work by breaking the chlorine ammonia bond ..neutralize the chlorine and convert NH3 to NH4 a(ammonium= less toxic).
I agree check to see if you have nitrates..it is possible you missed the nitrite tio nitrate stage but if you have nitrates this may indicate you already have both bacteria we desire.
I've had false readings involving nitrItes with Amquel plus reading nearly zero when I knew it was higher because I had just switched to Amquel plus when running out of the TOPFIN stuff. Amquel plus also binds nitrItes. I went back to the TOPFIN to continue my cycling and that's why I stopped using it....
To the OP.
I just went back and read your other cycling thread and you never once mentioned aeration, or filter. I don't mean to be anal but you do have a filter of some sort hooked up and running, yes?
You mention some aeration in this thread...What does that mean exactly?