7in1 is better than 6in1! Aquarium owners are happy to find they can test the most important water values of their aquarium water in 63 seconds. With the new JBL ProAquatest 7in1 they can not only determine the pH value, the general hardness, the carbonate hardness, the nitrite and nitrate value and the chlorine content, but now also calculate the CO2 saturation and read it out via a supplied table. CO2 deficiency is the most frequent cause of stagnating plant growth. One pack of JBL ProAquatest Easy 7in1 contains 50 test strips suitable for every freshwater aquarium.