Tetra Test 6-in-1A 60 second dip test for 6 essential water quality paramters. Tests for pH, Nitrite, Nitrate, KH (carbonate hardness), GH (general hardness) and Chlorine. Simply dip the test strip in the water for a few seconds, remove and then wait a minute for it to change colour. Compare the colours to the chart on the pack to get your readings. Always read the instructions before use. Testing every 2 3 days in newly set up aquariums, and once a week in