Seachem Reef Calcium

1 review

Seachem Reef Calcium additives help maintain healthy levels of calcium in your aquarium water to help your corals grow into a stunning reef. Easily applied to your tank, it comes at the very best prices from Swell UK with Next Working Day Delivery options.


  • Reef Calcium 100ml 10% OFF With Code
    code: seachem355 In stock Only 3 left in stock
  • Reef Calcium 250ml 10% OFF With Code
    code: seachem356 In stock Only 3 left in stock
  • Reef Calcium 500ml 10% OFF With Code
    code: seachem353 In stock Less than 10 in stock

Product Information

Seachem Reef Calcium is intended to maintain calcium levels and is a concentrated (50,000 mg per litre) bioavailable polygluconate complexed calcium intended to maintain calcium in the reef aquarium without altering the pH level. Simply put, this means that the substance is active straight away, for quicker results.

Polygluconate complexation has multiple benefits: it increases the absorption of the calcium, it provides a rich source of metabolic energy to help maintain peak coral growth, and it prevents calcium precipitation and alkalinity depletion.

It contains no nitrogen or phosphates, so it will not cause algae growth in a well maintained reef tank.

Reef Calcium can be used alone, or used with an ionic calcium supplement for superb results.


  • 100ml treats 1600 litres / 3519 gallons
  • 250ml treats 4000 litres / 880 gallons
  • 500ml treats 8000 litres / 1760 gallons


Add 1 capful (5 ml) per 80 litres, twice a week. You can increase the amount or frequency based on growth response but do not exceed 3 capfuls per 80 litres per day. Each capful will raise calcium by about 3 mg per litre.

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