The regular addition of trace elements is essential for the successful care of lower animals, higher algae (e.g. coralline algae), corals and fish. Although a large portion of trace elements is replenished by regularly changing the water, part of the trace elements and nutrients are already lost after a few days or have already been consumed by corals and other organisms. Also, a regular change of water cannot replenish the consumed trace elements to 100 %. To optimise and stabilise the water values, trace elements must therefore be regularly added to the aquarium.