pm2 and salinity probe

[Gaby_scan]

hello, i just installed a pm2 and after calibrating the probe 2 times i manage to get it to where it needs to be, my question is, why is my reading the same all the time meaning i have a flat curve on my fusion. correct me if i'm wrong but doesn't this need to change as water evaporates??? this is a new red sea max nano tank and i do not have an ato in it so i am doing it manually. the tank is still in cycle right now. thanks for any inputs.