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.
ledtime Reviewed by ledtime on . Yellowing - Form Completed & Pics I don't know what to do. Soil runoff is at 7.5 even after flushing with 3 gallons of 6.8. E-indoor or outdoor - INDOOR E-soil, soilless, coco, aero, or hydroponic - SOIL E-specific medium - FOX FARM OCEAN FOREST - STRAIGHT FROM BAG CSL-Soil type/brand - FOX FARM OCEAN FOREST - STRAIGHT FROM BAG SCL-Anything you have added to the soil - PH'D TAP WATER SCLR-Soil or slab runoff pH - 7.5 E-Water source - TAP E-Source water pH - ADJUSTED TO 6.8 Rating: 5