I just calibrated it as it's a brand new PH pen. And the RO system is brand new too. My source water is horrible though. 9.5-9.8 out of the tap. I'm sure an RO unit can only decrease the PH so much....

Keep in mind that the PH of the RO water out of the system is 7.5. I PH down'd the water to under 7.0 for the test just so I could see what increase if any there was.