Barium

Trace element present in sea water. It is consumed by corals and sponges. Its role is still little understood but must be monitored with ICP.

Detailed explanation

Barium in natural seawater is found at concentrations of approximately 5-15 ug/l (micrograms per litre). It is one of the most mysterious elements in aquarium hobby: it is known that it is consumed by corals and sponges but the exact mechanism is not entirely clear.

Some theories suggest that barium is incorporated into the coral skeleton and that adequate levels can improve growth and colouration. Other research indicates a role in sponge mineralization.

Barium is measured only with ICP analysis. Results are expressed in ug/l (micrograms) and not in mg/l like most other parameters. A value that is too high may indicate contamination from external sources.

The dosage of barium is controversial. Some additive manufacturers (such as Fauna Marin) include barium in their trace element systems. Most aquarists do not dose barium separately and rely on water changes to maintain the level.

If the ICP value is within range there is no need to intervene. If it is too low, water changes with a good salt should restore it. If it is too high it is a good idea to check the osmosis water and look for possible sources of contamination.

Reference values by aquarium type

How it is measured

Only via ICP-OES analysis.

What happens when it is too low

Possible effects on calcification but not documented with certainty.

What happens when it is too high

At high concentrations it can be toxic to invertebrates. Look for sources of contamination.

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