JBL ProAqua Test Combi Set Marin is a complete set to simply and safely test the most significant water parameters in your marine water aquarium. Having set up your marine aquarium the water values need to be measured between daily and weekly, to find out how well the aquarium is developing and when it is ready for the animals to be added. The carbonate hardness indicates the pH stability of the water. It should be between 7 and 10dKH. Ammonium is the first stage of the nitrogen decomposition and it increasingly changes into toxic ammonia with pH values above 7. The ammonium content must not exceed 0.25 mg/l. The nitrite value indicates whether this toxic compound for fish is present in the aquarium. Nitrite should always have a level below 0.2 mg/l. Nitrate and phosphate serve as food for algae. Nitrate values over 20 mg/l and phosphate values over 0.1 mg/l can lead to excessive algae growth. Many coral species grow significantly better with low nitrate and phosphate amounts since e