JBL ProAqua Test Combi Set Plus: valuable complete water test kit for a simple and save controlle of all important values in your aquarium biotope. The JBL ProAqua Test Combi Set Plus is available in two different versions:Combi-Set Plus NH3/NH45 different tests for the most important water values and the CO2 table:pH (3-10)Ammonium/Ammonia NH4/NH3Carbonate hardness KH (CH)nitrite NO2nitrate NO3Combi-Set Plus Fe5 different tests for the most important water values and the CO2 table:pH (3-10)Iron FeCarbonate hardness KH (CH)nitrite NO2nitrate NO3+ CO2 table+ laboratory compensation system compensates water discoloration+ includes syringe to measure amount of water+ water-resistant plastic case+ contains tables for recording results+ each test is available as refill pack