Test Items Total Alkalinity pH Hardness, Iron, Chromium, Bromine, Nitrate, Nitrite, Residual Chlorine, Fluoride and Sulfite. Test strips are suitable for drinking water, aquariums, fish tanks, swimming pools and spas, industrial water, ponds, spa water testing. High quality water tester with precise color coordination and high sensitivity, use professional healthy drinking water test paper to test water quality standards. Dip the drinking water test paper into water for 2 seconds, hold in air for about 1 minute, and then call back the color of the bottle to get a reading. The 50-piece pack of weekly water tests makes the drinking water test strips easy to use, even for beginners. Product Specifications Name: 16 in 1 Water Test Strips Colour:As Shown Material:PVC Package Contents: 1 set * Water Quality Test Strips(50 pcs) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.