Reef Strontium

  • Restores and maintains strontium to levels found in natural seawater
  • Strontium gluconate
  • Concentrated (10,000 mg/L


Strontium occurs in natural seawater at a concentration of about 8 to 10 mg/L. It is chemically very similar to calcium, and many organisms incorporate it in their skeletons along with calcium. Its addition to reef aquariums aids the growth of corals, coralline algae and other organisms that lay down a calcereous skeleton or shell, including tridacnid clams.

Reef Strontium™ is intended to restore and maintain strontium to levels found in natural seawater without affecting pH. Strontium is utilized in the same manner as calcium and holds a similar importance in maintaining a vigorous level of growth.

Reef Strontium™ contains 10,000 mg/L of available strontium as a gluconate complex. Gluconate complexation confers several benefits: it increases the bioavailability of the strontium, it provides a rich source of metabolic energy to help maintain peak coral growth, and it inhibits strontium precipitation/alkalinity depletion. Gluconate contains no nitrogen or phosphorous, thus it is biologically impossible for it to lead to algae growth in a properly maintained reef system.


BEGINNER: Use 1 capful (5 mL) per 80 L (20 US gallons) twice a week.

ADVANCED: Check strontium level, then follow addition regimen above until strontium is adjusted to 8–12 mg/L. Each 5 mL/80 L will raise strontium by about 0.6 mg/L. Quantity or frequency can be adjusted as required to maintain strontium.

EXPERT: After determining the strontium consumption rate, set up a continuous drip system. Use the following formula to determine how much to add to your top-off water: m=0.1vs (m=mL of product to add to top off water, v=volume of tank in liters, s=amount to raise strontium in mg/L). For example, if you want to raise strontium by 2 mg/L in a 200 liter tank, then you would add 0.1x200x2=40 mL into the top-off water. [For reference: 1 gallon=3.8 L].

NOTES: Use the Reef Status™ Strontium test kit to measure strontium.

Guaranteed Analysis

Amounts per 1 gram
Strontium (Sr) 10 mg

Ingredients: strontium gluconate


100 mL, 250 mL, 500 mL, 4 L

To reach your desired level use:

caps or mL

Make large adjustments slowly to avoid overshooting intended level

Considerations: We recommend a strontium level between 8-12 mg/L. It is advisable to make large adjustments slowly to avoid overshooting intended level. Excess strontium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement.

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0375 Reef Strontium 100 mL
0376 Reef Strontium 250 mL
0373 Reef Strontium 500 mL