In terms of accuracy, aquarium test kits are not exactly the most accurate option for measuring water quality. They may be accurate enough for most fish keepers, but they are not that precise. The difference between having a nitrate level of 0 and 0.1 might not seem like a big difference, but it can be. However, the average fish keeper probably won’t need this kind of precision. The only time you need precision like this is if you have rare and sensitive fish, corals, or aquarium plants. And you’ll also need precision and the perfect water parameters when you breed your fish.