I've tried many kits and I like the Salifert one the best. I gotta get one of my kids to tell me when the color changes though, purple to blue is really hard for me to see. Why can't they make these things go from yellow to blue
I'm in the pool so I can't look it up but I want to say 1650. I think they give instructions on diluting results to go above that. But even if they don't it's easy to figure diluted results on your own.
I've tried a few Mg kits over the years including Red Sea, Salifert and Tropic Marin Mg kits. I like the Tropic Marin Mg the best because its accurat and easy to use/read.