An aquarium contains just a tiny amount of water volume compared to natural waters. This has the disadvantage that all the water values can fluctuate from one extreme to the other in a very short time. However, a high level of stability and consistency is required for successful aquarium maintenance. The important thing here is a chemical analysis system that can be used to diagnose the water and can form a basis on which the cure (e.g. using water maintenance and filtration products) can be deduced.

Marine water aquaria in particular will not achieve the most important water values without regular checking. The concentrations of the key elements of calcium and magnesium especially are constantly changing in the aquarium, because they are consumed by corals and algae or are reduced by precipitation. Many organisms react very sensitively to such fluctuations in the water values.