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Rye Oil Shop


Magnesium Chloride 25kg Flakes 47% Sea Salt MgCl2




Magnesium Chloride Main Information:

  • Magnesium Chloride Hexahydrate
  • Molecular Formula: MgCl2.6H2O
  • CAS Number: 7791-18-6l
  • Appearance: Flakes


Also Known As:

  • Magnesium Dichloride Hexahydrate
  • Magnesium Chloride Still Salt
  • Magnesium Chloride


Key Properties:

  • Magnesium chloride hexahydrate is a naturally occurring salt with the formula MgCl2 6(H2O).
  • It is mostly produced from sea water and in particular the Dead Sea.
  • It is a colourless to white, odourless salt with a bitter taste.
  • It has been used for centuries as an aid to improving health and well being.
  • The main uses for magnesium chloride are in the paper, textiles, cement and refrigeration industries.
  • It also finds major applications as a de-icer and a water treatment in aquariums.
  • High quality magnesium chloride from the Dead Sea.
  • Free from phosphate, bromides and ammonia.
  • Dissolves quickly to provide clear solution.

Applications of Magnesium Chloride


Marine Aquariums:

  • Magnesium chloride hexahydrate is for adding magnesium to sea water.
  • Severely low values of magnesium (900 mg/L or below) can cause low pH values and an inability to maintain proper alkalinity and calcium values.
  • If magnesium becomes too low, coral growth will stop and followed by a decline in coral health.
  • Carbonates and calcium are essential for all growth of corals, coralline algae, clams and invertebrates.
  • Maintaining the correct magnesium values is very important and is indirectly responsible for coral and coralline algae growth by making it possible to maintain correct calcium, alkalinity and pH values.
  • The magnesium content must often be increased, as shortfalls in the content can arise for various reasons.
  • The normal magnesium content is around 1.30 – 1.40 mg/litre (1300–1400 ppm).
  • To increase the magnesium content you need magnesium chloride hexahydrate or a mixture of magnesium chloride and magnesium sulphate (ratio of 7:1).


How To Dose Aquariums:

  • 50g will raise Magnesium levels by approximately 60ppm in 100 litres of salt water.
  • It is not recommended to increase Magnesium levels by more than 60ppm per day.
  • Simply mix the required amount into a few litres of Reverse Osmosis Water, once dissolved, slowly add to your tank in an area of high flow, preferably over a period of an hour.
  • Alternatively add to your evaporation top up water and top up as normal.


Bathing / Soaks & Health use:

  • Soaking in magnesium salts has been shown to markedly improve skin hydration, speed wound healing, enhance skin barrier function, and decrease inflammation.
  • Taking a magnesium bath. Add 1-3 cups for a deeply therapeutic bath, 3 cups will give maximum benefit. The water should be warm and not too hot. This is an excellent way to deliver needed trace minerals directly to the body.
  • Foot bath. Soaking the feet in a magnesium foot bath also helps to replenish magnesium levels.
  • It is well documented that most of the magnesium in oral capsule supplements is lost in the digestive system or eliminated by the body, not reaching the cells that need it!
  • Transdermal Magnesium Chloride [absorption through the skin such as in a bath or spray] is a far superior method for safely increasing magnesium levels in the body, particularly useful for relieving sore muscles and joints, reducing pain related to functional magnesium deficiency and for replenishing depleted soft tissues. It also assists to help calm nerves and reduce systemic bodily stress. There is simply nothing else that so quickly, easily and safely raises magnesium levels in the body. It is an essential catalyst for many enzyme reactions, especially in regard to cellular energy production, for the health of the brain and nervous system and also for healthy teeth and bones. Magnesium in the form of magnesium chloride is also an impressive infection fighter. It is necessary for the metabolism of carbohydrates, fats and amino acids.
  • Additional benefits of magnesium chloride flakes include greater energy, more relaxed muscles [and stronger connective tissues], better sleep, improved mental function, alleviate headaches, arterial health, better reproductive function, and better hormonal balance for men and women [and reduced PMS]. In addition, magnesium maintains the detoxification of toxins and metabolic waste products. It also acts as an effective full body tonic increasing energy, strength and endurance related to the 350 enzymes directly related to magnesium.
  • Transdermal Magnesium application can help with the removal of toxins and heavy metals at a cellular level. Assists with the rejuvenation of sun damaged skin, sunspots, healthy hair and wrinkle reduction. Magnesium is directly linked to the body’s production of DHEA, often called the ‘Feel Good Hormone’. DHEA levels dramatically decline with age. Magnesium deficiency has been linked to decreased memory and learning ability. Increasing Mg levels can improve cognitive function in children, the elederly and those involved in stressful study. 27% of magnesium is found in the muscles. Transdermal Magnesium application can rapidly relieve muscle pain andreduce cramps associated with magnesium deficiency. Magnesium is a most important mineral supplement due to its loss through sweat. It can reduce fatigue and stress and is a component of every healthy muscle cell. Transdermal Magnesium application can help to relax and balance the nervous system to counter the stresses of modern life. Magnesium improves the immune system as a healthy immune system is driven by white blood cells that require good magnesium levels. Magnesium is essential to balance calcium intake.



Gardening and Horticulture:

  • Because magnesium is a mobile nutrient, magnesium chloride can be effectively used as a substitute for Magnesium Sulfate (Epsom Salt) to help correct magnesium deficiency in plants via foliar feeding.
  • It is advisable to use a smaller dose when using magnesium chloride compared to the recommended dose of magnesium sulfate (20 g/L).
  • This is due primarily to the chlorine present in magnesium chloride, which can easily reach toxic levels if over-applied and/or applied too often.


  • Generally, all ice melters work in the same way by depressing the freezing point of ice or snow and turning the mixture into a liquid or semi-liquid slush.
  • A number of state highway departments throughout the United States have decreased the use of rock salt and sand on roadways and have increased the use of solutions of magnesium chloride (often called “liquid magnesium chloride”) as a de-icer or anti-icer.
  • Magnesium chloride is less toxic to plant life surrounding highways and airports, and is less corrosive to concrete and steel (and other iron alloys) than sodium chloride.
  • The liquid magnesium chloride is sprayed on dry pavement (tarmac) prior to precipitation or wet pavement prior to freezing temperatures in the winter months to prevent snow and ice from adhering and bonding to the roadway.
  • Magnesium chloride is also sold in crystal form for household and business use to de-ice sidewalks and driveways.
  • In these applications, the compound is applied after precipitation has fallen or ice has formed, instead of previously.


Snow Removal:

  • The use of magnesium chloride seems to show an improvement in driving conditions during and after freezing precipitation.


Dust & Erosion Control:

  • Road departments and private industry may apply liquid or powdered magnesium chloride to control dust and erosion on unimproved (dirt or gravel) roads and dusty job sites such as quarries.
  • Its hygroscopy makes it absorb moisture from the air, limiting the number of smaller particles (silts and clays) which become airborne.
  • A small percentage of owners of indoor arenas (e.g. for horse riding) may apply magnesium chloride to sand or other “footing” materials to control dust.


Medical & Veterinary:

  • Magnesium chloride is a type of pharmaceutical preparation of magnesium.
  • Medically-prescribed magnesium supplements such as Slo-Mag and Mag-SR contain magnesium chloride which is slowly released from a matrix.
  • One veterinary study in 1989 indicated some effectiveness against tumors when magnesium chloride was used as a feed additive.


Other Uses:

  • Magnesium chloride is used for a variety of other applications besides the production of magnesium: the manufacture of textiles, paper, fireproofing agents, cements and refrigeration brine, and dust and erosion control.
  • Mixed with hydrated magnesium oxide, magnesium chloride forms a hard material called Sorel cement.



  • Formula: MgCl2.6H2O
  • Magnesium Chloride (MgCl2): 47%
  • Calcium Chloride (CaCl2): 2.2% max
  • Sodium Chloride (NaCl): 0.9% max
  • Potassium Chloride (KCI): 0.6% max
  • Water of Crystallization: up to 100%
  • Sulphates (SO4): 0.025%
  • Magnesium Oxide (MgO): 0.1% max
  • Iron (Fe): 10 ppm max
  • Heavy Metals (Pb, Hg): 0.1 ppm max
  • Arsenic (As): 0.1 ppm max
  • Cadmium (Cd): 0.01 ppm max
  • pH of Aqueous Solution: 8.2

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