JBL Nitrite Test NO2 Quick test to determine the nitrite content in freshwater marine water aquariums and in ponds Simple and reliable monitoring of the aquarium pond water values. Checks the biological balance (bacterial activity) in freshwater and marine water Laboratory comparator system to compensate any inherent water colouring: fill glass vials with sample water, add reagents to another vial, place vials in holder, read values on colour chart When to use: when setting up a new freshwater aquarium: daily for 3 weeks. Initial setup with marine water: once a week. For use in case of fish diseases or fish deaths. Online Laboratory: free analysis and recommendations for the water values you have measured Package contents: 1 quick test, Nitrite Test NO2. Contents for approx. 50 measurements. Incl. 2 reagents, 2 glass vials with screw cap, syringe, comparator block and colour scale. Refill ingredients available separatel