Nitrite Test Kit

The API (Aquarium Pharmaceuticals) Nitrite Test Kit is a liquid test kit used in both freshwater and saltwater aquariums to measure nitrite (NO₂⁻) levels in the water. Nitrite is one of the most important parameters to monitor during the nitrogen cycle because it’s toxic to fish and invertebrates even at low levels. What it does Measures nitrite concentration in aquarium water Helps track tank cycling progress Identifies dangerous spikes during fish-in cycles or system crashes Range & accuracy Typically reads from 0 to ~5 ppm (mg/L) Color chart-based comparison (pink/purple scale) Designed for hobby-level but reliable reef/freshwater monitoring