Review on 🌊 180-Test Freshwater and Saltwater Aquarium Nitrite API Test Kit - Complete API Nitrite Testing for Optimal Water Quality by Maria Hanson

Because I don't have accurate scientific equipment to compare test results, I can't say if they are accurate or not. I just have to go by faith. I have a problem with a color coded card. I don't know why it jumps from 2.0ppm to 5.0. Also, the purple tones are about the same at these two values. In bright light, purple is naturally (very) slightly darker at 5.0 than at 2.0; However, since you need to compare the color of the glass tube to the chart, the colors of the two values are almost indistinguishable, as are the colors for 0.25, 0.50, and 1.0. Unfortunately, I don't find the test very helpful. All shades of purple are too similar to make an accurate diagnosis.