Yes, that's correct, later in the article it says to raise to 4-5ppm at the end of the fishless cycling. Its ideal to -end- the fishless cycling process being up at 5ppm and dropping to double-zeros within 10-12 hours as the signal to start your "qualifying week." Its a judgement call deciding which nice dark green slightly above 4ppm is what you would call 5ppm if you're looking at the API results. The significant thing is just that it matches or exceeds that 4ppm color on the chart nicely and that you've watched it repeatedly accomplish the 12 hour drops day after day that last week. It -has- to be a nice robust set of colonies if it can do that and it'll be the kind of colonies that can respond quickly to fish stocking additions.
In the first phase of fishless cycling, prior to the "nitrite spike," its fine to just raise it to 3 or 4ppm. Its only at the end that the 5ppm matters for the robustness.
~~waterdrop~~