Reef Calcium 500 ml — Organic Calcium Polygluconate 50,000 mg/L | Seachem

Seachem Reef Calcium is a concentrated liquid organic calcium supplement at 50,000 mg/L, based on calcium polygluconate. Designed to maintain calcium levels in reef aquariums without altering the pH, it offers superior bioavailability compared to traditional ionic calcium due to its uncharged organic form, allowing corals to absorb calcium with less energy.

Main advantages

• Concentrated organic calcium polygluconate at 50,000 mg/L — high bioavailability for corals
• No impact on the aquarium's pH
• Contains neither nitrogen nor phosphorus — does not cause algae growth
• Provides a source of metabolic energy directly assimilable by corals
• Prevents calcium precipitation and alkalinity depletion

Use in reef aquariums

Reef Calcium uses chained organic calcium rather than ionic calcium. When an uncharged molecule is absorbed, the coral acquires several calcium atoms along with an easily metabolized carbohydrate, with less energy expended than with ionic calcium. Reef Calcium can be used alone to maintain calcium levels, but it provides superior coral growth when combined with an ionic supplement such as Seachem Reef Advantage Calcium or Seachem Reef Complete. In cases of severe calcium deficiency, perform a water change or use an ionic supplement to restore levels.

Dosage

• Standard: 1 capful (5 ml) per 80 L (20 US gallons), twice a week
• Adjustment: Increase the quantity or frequency according to the growth response, without exceeding 3 capfuls (15 ml) per 80 L per day
• Each 5 ml capful increases calcium by 3 mg/L
• Maintain calcium levels between 380 and 420 mg/L. It is not necessary to exceed 380 mg/L with this product.

Manufacturer's precautions

• Do not mix directly with a carbonate supplement — alternate days or wait at least 30 minutes between doses
• Excess calcium can accelerate the loss of carbonate alkalinity.
• Color and clarity may vary from batch to batch.
• The crystals around the cap are normal and will dissolve when you shake the bottle.
• Unlimited shelf life

Ingredient

Calcium gluconate. Content per gram: calcium minimum 50 mg, maximum 52 mg.

Available formats

• 100 ml
• 250 ml
• 500 ml
• 4 L

Why choose Reef Calcium from ReefSolution?

For complete reef calcium management, use Seachem Reef Calcium as a secondary supplement in combination with Seachem Reef Advantage Calcium or Seachem Reef Complete as the primary ion source. Supplement with Seachem Reef Carbonate for alkalinity and monitor your parameters with the Salifert Calcium Test Kit or the Hanna Checker Calcium.

Frequently Asked Questions

What is the difference between Seachem Reef Calcium and Reef Advantage Calcium?

Reef Calcium is an organic calcium polygluconate for calcium maintenance with high bioavailability. Reef Advantage Calcium is a concentrated ionic calcium supplement to increase levels. Seachem recommends using Reef Advantage Calcium as a primary supplement and Reef Calcium as a secondary supplement.

Does Reef Calcium cause algae?

No. Polygluconate contains neither nitrogen nor phosphorus. It cannot cause algae growth in a properly maintained reef system.

Do standard calcium tests detect Reef Calcium?

Yes. Reef Calcium is a complexed calcium and most tests on the market, including Salifert, detect it correctly.