Kit is straightfoward to use. There's a business-card size set of icons on the flip side of the color scale that guide you through usage, and it's easy enough that you can figure it out solely from the pictures (there is also a verbose manual in the kit). I find the liquid readout easier to decipher than dip-strips. For most cases in an established aquarium, this test kit will provide the information that you need. Oftentimes you either have zero nitrite, or too much nitrite, and in the case of the latter, this kit is able to tell you whether you have more or less now than when you last tested.A word of caution for anyone doing fishless cycling of a tank: if you oversaturate this test reagent, it will read 0 ppm nitrite at the 5 minute time point. It takes around 100 or greater ppm nitrite to achieve this, and if you're oversaturating, you will see the reagent turn deep purple immediately, then slowly turn pale greenish-blue over time. If you're suspicious that the reading is oversaturated (this only applies if you're cycling a tank without fish, where you might incur substantial nitrite buildup but there are no fish to alert you by dying): just dilute the tank water 10 or 20-fold and test again to confirm your first result. Extending from this: if you're having a hard time measuring high amounts of nitrite because the shades of purple are too similar, just dilute your tank water a known amount, then read and multiply the result by the amount that you know you diluted.