It will likely climb again a bit once you stop. If you let it be, the aragonite and bacteria will worth together to bind/swap it and they can keep it under control on their own. ...unless you have a filthy tank or something.
Also, I might suggest a better N test kit than API. I have never found them too terribly reliable, but others may disagree.
My personal number are: clear on Salifert for N and P tests from the top, but some color from the side on the N. These are well below 1 and .01 and very close to zero, but not at zero. The tank handles this equilibrium on it's own - I have pretty good stock of 3 Genicanthus, 9 Anthias, Purple Tang and a handful of wrasses in a 120G.