I didn’t like the first nitrate Hanna kit but apparently the next one was easier to useI’d imagine there are a lot of opinions out there. I use the Hanna checkers for phosphates (ULR), nitrates, and alkalinity. I know it’s $200 worth of test kits, but it’s worth it considering what they charge for coral these days. I’m sure there are people who would disagree, but I’m getting the results I’m looking for.
I have heard Hanna calcium kit is a pita to use as well