Jus take a look them everytime u get home wun hurt much rite? Adjust it accordingly if u have to. Will it really matter if ur gears are in too low RH or too high RH for couple of hours (be it 30% or 60%)? if it does, then i suppose u got to bring a dry box out when u are out for ur photo shoot. ;p
When I bought it new back then, I turned the knob all the way clockwise for it to go down till 40%, then I turned the knob back CCW to one o'clock position and it has been that way since and my reading is always at 45% in my room temperature of 25deg.