D-D H2Ocean Portable Refractometer Salinity Checker– Seawater Marine Auto Top Off Calcium and magnesium levels are

Calcium and magnesium levels are designed to replace those that are used up through coral growth within the aquarium

Avoid small aquariums

provide frequent portions of dried marine algae

sterile or bare-bottom systems where there is not enough natural food

D-D H2Ocean Portable Refractometer Salinity Checker– Seawater Marine Auto Top Off Calcium and magnesium levels areD D H2Ocean Portable Refractometer Salinity Checker Seawater Some of the refractometers currently available to the aquarium hobby are designed for measuring saltwater (sodium chloride or brine solution) and not true seawater. Although seawater is mostly sodium chloride it also contains other elements such as magnesium and calcium that change the refractive index slightly and will give a slightly different result. The most common symptom of this