Sounds to me like possible meter problems. Is it a Hannah?
Before taking apart your RO, I'd go get one of those freshwater aquarium ph test kits. $6.00 or so. Check it against your meter and see if there is a difference. Doubtful there would be anything in the RO system that could possibly raise ph.
Rusty Trichome Reviewed by Rusty Trichome on . New RO system raising ph Just picked up a 100 gpd ro system. Ran it for about 40 minutes first to clean it out like the instructions said, then filled up a 5 gallon bucket. Ph'd the water after and the filter raised it from the 7.3-7.5 range to 10. Is this normal? Do I just need to let it run awhile to clean it out? Rating: 5