EASY TEST 6 IN 1 6-fold test strips for tests with clear orientation -50 test strips -With a chlorine test (disinfect in tap water) -pH test from 6.4 to9.0 (acid content of water) -KH test from 0 to 20 dKH (pH-stability of water) -GH test from <1 to> 21 dGH (general hardness) -Nitrite (NO2) from 0 to 10mg/L (poisonous nitrogen compounds) -Nitrate (NO3) from 0 to 250mg/L (cause of algae)