Fast and Easy Steps for Testing: Step 1: Collect water samples in the plastic tube (Not Included). Step 2: Immerse the test strip in the desired water sample and remove within 1-2 seconds. Step 3: Hold the strip horizontally and gently tap or shake to remove excess water Step 4: Read the test results carefully within 60 seconds in a good light and with the test area held near the color chart on the bottle label. They are perfect for testing drinking water, pools & hot tubs, spas, freshwater, spring water, hydroponics, aquariums, aquaculture, science experiments and more. The results are fast, most within minutes, and very easy to read by following along with our color charts and instruction manual. Details: size:5.3*5.3*14.4cm/2.08*2.08*5.66inch Materials: water quality test paper Color: as the picture shows Style: 50 Strips, 100 Strips Package Contents: 16 in 1 Water Test Strips (50 Strips) Or16 in 1 Water Test Strips (100 Strips) Notes: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data. Everything you need to test your water; tests for 16 parameters, ensures lead free and pH safe drinking water; testing tube and dropper included in every kit for easy sample collection Easy, Fast and Accurate: Put the test strips in water, take it out, and compare with the color chart. It only takes 60s to know that the indicators of the detected water are low, normal and high quality.Take care of family health. Ability to test the most important parameters of water: Hardness / pH / Fluoride / Lead / Mercury / Nitrate / Nitrite / Residual chlorine / Total chlorine / Bromine / Carbonate / Total alkalinity / Zinc / Aluminum / Cyanuric Acid Widely Application: They are perfect for testing drinking water, pools & hot tubs, spas, freshwater, spring water, hydroponics, aquariums, aquaculture, Industrial waste water, science experiments and more.