Sodium
The most abundant element in sea water after chlorine. It contributes to the salinity and osmotic balance of aquatic organisms.
Detailed explanation
Sodium (Na) is present in natural sea water at approximately 10.800 mg/l. Together with chlorine it forms sodium chloride which constitutes approximately 85% of the salts dissolved in the ocean.
In aquariums, sodium is never dosed separately. Its concentration is determined by the overall salinity. If the salinity is correct (35 ppt) the sodium is automatically in range.
An ICP analysis showing abnormal sodium compared to the natural range may indicate a synthetic salt with an unbalanced profile. Some cheap salts have different ionic ratios than natural seawater.
In freshwater aquariums sodium comes from tap water and from the metabolism of organisms. It usually doesn't cause any problems. The addition of table salt (NaCl) to treat some diseases of freshwater fish is an ancient practice and still valid for certain pathologies. It is used at a concentration of 1-3 grams per litre for short periods.
In brackish water sodium is obviously present in quantities proportional to the desired salinity.
Reference values by aquarium type
| Aquarium type | Recommended range |
|---|---|
| Marine (reef) | 10500 - 11000 mg/lNSW: approximately 10800 mg/l. Determined by salinity |
How it is measured
Via ICP-OES analysis. In practice, salinity monitoring is sufficient.
What happens when it is too low
Indicates salinity too low.
What happens when it is too high
Indicates too high salinity or salt with an unbalanced profile.
Coralia Lab monitors this parameter with AI diagnostics. Tank Score alerts you when a value moves outside the recommended range for your aquarium.
Try ICP analysis with AI for free