i went with a Camp Chef off Amazon. very reasonable price wise. i was leaning toward one of the built like a brick shit house ones for big $$$$ but this one has been really all i needed.
that's the way i do it. my target was 3 ppm so 0.3 grams per 10 gallons water. it dissolves fairly quickly: you could always add it to a little jug of warm water and shake then dump