Buy quat test paper in 15 foot rolls for 0-400ppm range & get results in just 1-2 seconds; comes with color chart & only $8.25.
See Details below for instructions on how to get the best results every time.
They come in a reusable plastic dispenser with a 15 foot roll that can be torn into individual usable strips. If used carefully, they can be very economical with ~175 tests possible if short, ~1" pieces are used. The sensitivity and speed of these is similar to our individual strip versions.