Canadian tire TDS meter

[new but handy]

Hey all; right now Vernon tap water up east hill is about 230 ppm
bottled water from london drugs is 5-10 ppm
and my ro unit is 1 ppm
I assume with all the boil water advisorys in the summer the tds would go way up. If I remember correctly the tds at my place in aug or sept was around 425 ppm. But I probably don't remember correctly.
my tank reading tips the scale with a flashing 999. I guess the meter won't read salty aquarium water, or there is a lot of stuff in there!