I recently had hydrotech RO (the current 1240 M model) system installed it pulls water after the water softener; and also purchased a TDS and PH meter.
It doesn't seem to consist of any mineral cartridge that would make the water harder, yet when I measure the PH of my RO water is approx. 9.5-9.7, while my tap was is around 8.8-9.0 (about a point higher). I thought water was supposed to become more acidic that standard tap water with an RO system. The PH meter seems correct, I have calibrated it with different PH solutions per it's directions.
The RO water is running through all plastic lines. My TDS is about 7 most times. Any ideas? Is it safe to drink water in the high 9's for PH?