With every fishless cycler, its always interesting at this point to see whether the N-Bacs have truly crossed over in colony size and will show ZERO from now on or whether the testing of them was fluctuating a bit and some nitrites will still be seen at the 12 hour mark.
Since the science tells us that each cell on average splits into two about every 24 hours given ideal conditions, and the colony is in the millions (or some sort of huge size) now and showing its growth via the "times to zero" getting shorter and shorter, we expect the growth curve to be very steep. That should mean that we pass the "12 hours to drop to zero" mark in a single day and from then on you just won't ever see any purple again at the 12 hour mark.
So each time a fishless cycler gets here, it gets interesting to see whether their data will seem to support this view, or by not doing this, to show that there is something more complicated.
~~waterdrop~~