HKM-195923 Six-in-One Aquarium Water Quality Test Strips for Hardness, Nitrate, Nitrite, Chlorine, Carbonates, pHIntroducing the HKM 195923 Six in One Aquarium Water Quality Test Stripsa must have for any aquarium enthusiast looking to maintain a healthy aquatic environment. These test strips are designed to provide reliable results for six key water quality parameters, ensuring that your fish and plants thrive. Made from durable PVC, the HKM 195923 is user friendly, allowing you to quickly assess the quality of your aquarium water. The test elements include: