I wonder if the unit was changed in the last few years. My unit is probably 5+ years old and I don't remember getting any solutions with it. I also thought I remember it stating you could use distilled or RO water to calibrate it. I've always used RO/DI and it reads my calibration solution correctly and it and my hanna read the same.
I wonder if they say no RO now because to many people were using RO water with a high tds that was effecting the calibration.
