Determines the optimal nitrate value for perfect plant growth or possible cause of algae growth in freshwater and marine water Laboratory comparator system to compensate the inherent water colour: fill glass vials with sample water, add reagents to one vial, place vials in holder, read values off colour chart Use: when setting up a new freshwater aquarium: 1 x weekly. When setting up a new marine aquarium: 1 x weekly. With green algae problems You will find detailed information and troubleshooting tips about water analysis on the JBL website in Essentials/Aquarium or Pond Package contents: 1 nitrate test for approx. 40 measurements, incl. 2 reagents, 2 glass vials with screw caps, syringe, dosing spoon, comparator block and colour scale. Reagent refill separately available