Should be able to find a handheld TDS meter at Canadian Tire, WalMart or some other big box reno type location. Look in the RV aisles, that's usually where they put them, for people to check the TDS when they're out camping & want to know a little bit about the water quality. Should be less than $20 & is a good start until you get an inline unit.
Buckeye Field Supply in the US now offer a triple probe inline meter! Not local for you in the Fraser Valley, but they stock pretty much anything & everything with regard to RO systems. Always on the money with their advice too, check out their FAQ page, a lot of good info there.
http://www.buckeyefieldsupply.com/sh...ry=208&Sub=149