Cycling question (urgent)

[MitchM]

Never had that problem. Probably because it doesn't actually change the ammonia readings at all,it just makes the ammonia non toxic.

In other words, you don't actually know what the toxic NH3 level is.
You only know what the combined level of NH3 and NH4 is.

Prime has to be added regularily because the bond will break after a short period of time.
Meanwhile, your fish are constantly producing more NH3.
That's why I say Prime should only be used in an emergency.