You can just turn off skimmer or any pumps that intro air, turn off lights, plastic and tape seal top of tank, and just run PH's.
Many do this, no sweat, I use to work for a termite Co.
Just need to make sure they know what you are doing or they could pull that stuff out and just set in yard, seen it happen.
There's a fine line between owning your tank, and having your tank own you!_________________________________________
120G SCA starfire, tunze 1073.02 return pump, Geisemann reflexx 4xT5, 2x panorama pro LED strips, 2x Vortech MP 20's, 40g sump w/ fuge.