Attention! Reef Salt™ has been discontinued and replaced by our new and improved sea salt, Vibrant Sea™. Click here to learn more about Vibrant Sea™.

Reef Salt

  • Specifically designed to replicate replicate natural reef waters
  • Fast dissolving
  • Superior calcium and alkalinity stability


Reef Salt™ is a chemically sound blend of salts designed to replicate natural reef waters. It is specifically formulated for the reef environment and will provide ideal seawater concentrations of magnesium, calcium, and strontium with proper alkalinity and pH for closed reef aquarium systems. It contains all essential major, minor, and trace components found in natural reef waters, but contains no toxic or non-essential components such as nitrate, phosphate, silicate, arsenic, cadmium, or beryllium. Reef Salt™ dissolves quickly and completely and is ready to use in only a few minutes. Reef Salt™ will support and promote enhanced calcium and alkalinity stability for those wishing to maintain calcium above Natural Sea Water (NSW) levels (400 mg/L) as well as providing NSW levels of bromide (65 mg/L).

For marine only environments, use Seachem Marine Salt™ instead. It is specifically designed to meet the requirements of a marine only (not reef) system.


  1. Mix Reef Salt™ with dechlorinated tap or purified water. We recommend the use of a commercial dechlorinator like Prime® to neutralize any tap water chlorine and/or chloramines. If source water quality is extremely poor we recommend purification with a Seachem Pinnacle™ RO/DI system.
    NOTE: To prepare small quantities, use 34 g of Reef Salt™ per each liter (1/2 cup per each US gallon) of water.
  2. Stir well to ensure a good mix. Although the Reef Salt™ solution may be used immediately, we suggest aerating the water until it achieves oxygen/carbon dioxide equilibrium.
  3. Measure specific gravity. Recommended range is 1.020 – 1.025 at 24 °C (75 °F).
    NOTE: 675 g of Reef Salt™ is formulated to create 20 liters (1.4 lbs per 5 US gallons) of saltwater at a specific gravity of 1.021.
  4. Adjust salt level accordingly. If specific gravity is too low, add more Reef Salt™. If too high, add more dechlorinated or purified water.
  5. Change 20% of aquarium water every 2 weeks (or as necessary) to maintain optimum water quality.

USAGE NOTE: NEVER mix salt in an aquarium containing animals. In New Aquariums: Transfer animals to the aquarium AFTER salt is completely mixed and aerated and specific gravity has been adjusted. Use Seachem’s Stability® to avoid “new tank syndrome” and prevent unnecessary animal losses in a new system.

CAUTION: Reef Salt™ is not for human consumption. Keep out of reach of children. Contact in dry form may cause skin or eye irritation. In case of eye contact, completely flush eye(s) with cool water and seek medical attention..

NOTE: Depending on specific gravity, alkalinity should be about 4.0–5.0 meq/L, calcium should be between 380–430 mg/L, magnesium should be between 1200–1350 mg/L, and strontium should be 8–12 mg/L. Between water changes some elements may become depleted through utilization. Seachem offers a full line of reef supplements for restoring and maintaining many parameters, including (but not limited to) calcium, magnesium, strontium, iodide and alkalinity.


189 L (50 US gallons), 600 L (160 US gallons), 750 L (200 US gallons)

Typical Ionic Concentrations of Reef Salt™. Units=mg/L. Levels will vary based on salinity.
Chloride 19,336
Sodium 10,752
Sulfate 2,657
Magnesium 1,317
Potassium 421
Calcium 442
Carbonate/Bicarbonate 142
Strontium 9.5
Boron 16
Bromide 64
Iodide 0.060
Lithium 0.3
Silicon <0.1
Iron 0.0098
Copper 0.0003
Nickel <0.015
Zinc 0.0107
Manganese 0.0023
Molybdenum 0.0098
Cobalt 0.0004
Vanadium <0.015
Selenium <0.019
Rubidium 0.118
Barium 0.04

A: Our Reef Salt™is better for the following reasons: (a) provides a stable level of calcium and alkalinity, (b) stable long term pH, (c) more magnesium (d) less ammonia content, (e) no silicate based drying agents used [i.e. no more brown diatom algae often seen with other salt mixes], (f) the black container protects trace elements from decomposition due to light or moisture (a problem with white punctured bags), (g) use of more soluble calcium and magnesium carbonates/borates, (h) no phosphate, no nitrates present (i) the higher borate content allows for both better pH control and higher stable calcium levels.

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0321 Reef Salt 189 L (50 US gallons)
0323 Reef Salt 600 L (160 US gallons)
0324 Reef Salt 750 L (200 US gallons)