Drs. Foster and Smith Magnesium Sulfate offers experienced aquarists a convenient bulk additive to easily maintain the magnesium level in aquarium water. Just 1 tsp of Magnesium Sulfate per 10 gal of water raises magnesium 10 ppm. Use alone or in conjunction with our Magnesium Chloride to more closely match the natural ratio of seawater. With proper magnesium levels, you can enjoy the correct balance of calcium and alkalinity in your aquarium water to support continued coral health. For use in marine/reef aquariums only. Please note: Always test magnesium levels prior to use. Also, do not add Magnesium Sulfate directly to your aquarium water.
Shop all Marine/Reef Magnesium Supplements.
Do not add Magnesium Sulfate directly to your aquarium water.
Always test magnesium levels prior to use. Magnesium concentration found in natural seawater is between 1,250-1,350 ppm. Due to the sensitivity of marine organisms, it is not advisable to raise magnesium by more than 100 ppm per 24 hours.
Dosage: Add 1 teaspoon (3.5 g) per 10 gallons to raise magnesium by approximately 10 ppm. Dissolve appropriate amount in RO/DI water, then slowly add solution to a high-flow area, ideally into a sump. Re-test and repeat dose until desired level is reached.
Magnesium Sulfate can be used in conjunction with Magnesium Chloride to more closely match the natural ration of seawater.
Note: Due to the variation of granular size, conversion between volume and weight of powdered products is approximate. As a precaution, dose less than the calculated amount and measure the effect before adding the total amount.
Caution: This product becomes hot when mixed with water; use rubber gloves. Avoid contact with eyes, skin, and clothing. Wash hands after handling.
Storage: Store in a cool, dry place with lid tightly closed. Keep out of reach of children.