Mardel (Virbac) AMD21171 4-Pack Freshwater Aquarium Water 5-in-1 Test Strip Aquarium 5 in 1 freshwater water test strips makes testing easy Designed to be accurate and dependable while being safe and easy to use Features measure pH, hardness, alkalinity, nitrite and nitrate levels Easy read color chart makes matching the color on the strip pad easy Includes 4 strips per pack