Do they have alkalinity in both ppm and dkh ?
Yes
This and Nitrate HR. The only three that are worth it.
What is the magnesium kit like ?
Not enough data ti know for sure it works but magnesium test kits across the board are very inaccurate. I think i own themAll and the Aquaforest is the most consistent.
I rarely ever test cal or mag.
www.saltwateraquarium.com
I use the calcium checker and I actually like it. I don't use the syringes that they provide. I think it's too heard to measure amounts of liquid accurately. I'd recommend getting a 1-5 ml micropipette off of amazon to increase consistency between samples. It's not super nice, like the German made ones we use in the lab but good enough.
Yup clean and spotless is the key. After I do my testing I rinse out the cuvette and fill them up with distilled water, cap it and put back in its storage box. Also I bought a pack of these specialty glass wipes from Amazon. They actually polish the glass very well.
That's absolutely a great point. These Hannah checkers are not lab grade equipment, rather an affordable tool for the hobbyist. The way I look at it and this is just mho you can't rely on your own rodi water.. there's too many variables with that. I'm not a scientist nor a chemist but I am someone who can think outside of the box and I have my own conclusion that some may and may not agree with. I believe in a baseline, for testing I only use distilled water from a local store that sends out their water to be tested every two weeks and anytime I ask they can show me the latest results. As for my aquarium water I use RO and also sends water samples off every two weeks for results. He can tell me how much nitrates or calcium and phosphates etc. If I don't have distilled water from my local store then I don't test because I have been lost my baseline.
