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Calcium / Kalkwasser

Aquarium Calcium & Aquarium Kalkwasser Additives
Aquarium Kalkwasser
Aquarium Kalkwasser is the German term for a saturated solution of calcium hydroxide in water. Kalkwasser replenishes the calcium used during the growth of stony corals, coralline algae, clams, etc. Other benefits of kalkwasser include the precipitation of phosphate, maintenance of pH and alkalinity, and enhanced protein skimming. Aquarium kalkwasser can either be introduced into the tank or sump using a Kalkwasser Dosing system.

Aquarium Calcium
It is necessary to add aquarium calcium to reef aquariums in order to replenish the calcium utilized in the growth of soft and stony corals, pink coralline algae, calcareous algae, tridacna clams, and other invertebrates found in captive marine systems. Calcium can be added directly to the tank/sump. Aquarium calcium can also be introduced using a Calcium Reactor (which uses a different media than the calcium offered in this section).
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Brightwell Aquatics Calcion Liquid Calcium Supplement, 2 liters Brightwell Aquatics Calcion Liquid Calcium Supplement, 2 liters

  • Highly-concentrated ionic calcium solution
  • Increases the concentration of calcium in marine aquarium water to provide corals and other reef-building invertebrates with one of the most important elements required for growth
  • Is ionic rather than chelated, and contains no unwanted organic material such as EDTA, gluconate, or polygluconate
  • Over 50% stronger than most competing products
  • Free of phosphate, silicate, and organic material
  • Formulated by a marine scientist

Our Price: $31.00
In Stock
Brightwell Aquatics Calcion Liquid Calcium Supplement, 250 ml Brightwell Aquatics Calcion Liquid Calcium Supplement, 250 ml

  • Highly-concentrated ionic calcium solution
  • Increases the concentration of calcium in marine aquarium water to provide corals and other reef-building invertebrates with one of the most important elements required for growth
  • Is ionic rather than chelated, and contains no unwanted organic material such as EDTA, gluconate, or polygluconate
  • Over 50% stronger than most competing products
  • Free of phosphate, silicate, and organic material
  • Formulated by a marine scientist

Our Price: $6.30
In Stock
Brightwell Aquatics Calcion Liquid Calcium Supplement, 500 ml Brightwell Aquatics Calcion Liquid Calcium Supplement, 500 ml

  • Highly-concentrated ionic calcium solution
  • Increases the concentration of calcium in marine aquarium water to provide corals and other reef-building invertebrates with one of the most important elements required for growth
  • Is ionic rather than chelated, and contains no unwanted organic material such as EDTA, gluconate, or polygluconate
  • Over 50% stronger than most competing products
  • Free of phosphate, silicate, and organic material
  • Formulated by a marine scientist

Our Price: $10.90
In Stock
Brightwell Aquatics Calcion-P Dry Calcium Supplement, 200 grams Brightwell Aquatics Calcion-P Dry Calcium Supplement, 200 grams

  • High-purity powdered calcium
  • Increases the concentration of calcium in marine aquarium
    water to provide corals and other reef-building invertebrates
    with one of the most important elements required for growth
  • Stronger and more economical than liquid calcium solutions;
    created for hobbyists maintaining multiple reef aquaria
  • Formulated by a marine scientist

Our Price: $8.80
In Stock
Brightwell Aquatics Calcion-P Dry Calcium Supplement, 400 grams Brightwell Aquatics Calcion-P Dry Calcium Supplement, 400 grams

  • High-purity powdered calcium
  • Increases the concentration of calcium in marine aquarium
    water to provide corals and other reef-building invertebrates
    with one of the most important elements required for growth
  • Stronger and more economical than liquid calcium solutions;
    created for hobbyists maintaining multiple reef aquaria
  • Formulated by a marine scientist

Our Price: $13.70
In Stock
Brightwell Aquatics Calcion-P Dry Calcium Supplement, 800 grams Brightwell Aquatics Calcion-P Dry Calcium Supplement, 800 grams

  • High-purity powdered calcium
  • Increases the concentration of calcium in marine aquarium
    water to provide corals and other reef-building invertebrates
    with one of the most important elements required for growth
  • Stronger and more economical than liquid calcium solutions;
    created for hobbyists maintaining multiple reef aquaria
  • Formulated by a marine scientist

Our Price: $18.00
In Stock
Brightwell Aquatics CoraLazarus High-Purity Calcium Media, 1000 grams Brightwell Aquatics CoraLazarus High-Purity Calcium Media, 1000 grams


  • High-purity natural mineral that may be employed in traditional calcium reactors, or even blended in to pre-existing aquarium substrate, to gradually increase and maintain the calcium concentration and alkalinity in marine aquaria
  • Strong source of calcium, the most abundant cation by percent mass in aragonite, the mineral secreted by reef-building organisms to form skeletal material
  • Through dissolution, provides calcium, magnesium, strontium, potassium, and carbonates
  • Aids in increasing alkalinity to stabilize pH and encourage rapid biogenic aragonite formation
  • Optimal average particle size for use in media reactors and calcium reactors
  • Free of chloride and sulphate

Our Price: $8.00
In Stock
Brightwell Aquatics CoraLazarus High-Purity Calcium Media, 5 Kg Brightwell Aquatics CoraLazarus High-Purity Calcium Media, 5 Kg


  • High-purity natural mineral that may be employed in traditional calcium reactors, or even blended in to pre-existing aquarium substrate, to gradually increase and maintain the calcium concentration and alkalinity in marine aquaria
  • Strong source of calcium, the most abundant cation by percent mass in aragonite, the mineral secreted by reef-building organisms to form skeletal material
  • Through dissolution, provides calcium, magnesium, strontium, potassium, and carbonates
  • Aids in increasing alkalinity to stabilize pH and encourage rapid biogenic aragonite formation
  • Optimal average particle size for use in media reactors and calcium reactors
  • Free of chloride and sulphate

Our Price: $30.90
In Stock
Brightwell Aquatics Kalk+2 Kalkwasser Supplement, 1.8 KG (4 lbs) Brightwell Aquatics Kalk+2 Kalkwasser Supplement, 1.8 KG (4 lbs)


  • Contains calcium, strontium, and magnesium in the same ionic ratios found in aragonite. This unique feature increases the usefulness of Kalk+2 to reef-building invertebrates such as corals, clams, calcareous algae, etc
  • Provides temporary alkalinity and helps maintain pH within the desired range when used as directed
  • Adds no conservative elements, such as chloride, to the aquarium
  • Improves upon the industry-standard powdered calcium supplement over the past three decades
  • Formulated by a marine scientist

Our Price: $48.80
In Stock
Brightwell Aquatics Kalk+2 Kalkwasser Supplement, 100 grams Brightwell Aquatics Kalk+2 Kalkwasser Supplement, 100 grams

  • Contains calcium, strontium, and magnesium in the same ionic
    ratios found in aragonite. This unique feature increases the
    usefulness of Kalk+2 to reef-building invertebrates such as corals, clams, calcareous algae, etc
  • Provides temporary alkalinity and helps maintain pH within the
    desired range when used as directed
  • Adds no conservative elements, such as chloride, to the
    aquarium
  • Improves upon the industry-standard powdered calcium
    supplement over the past three decades
  • Formulated by a marine scientist

Our Price: $7.00
In Stock
Brightwell Aquatics Kalk+2 Kalkwasser Supplement, 225 grams Brightwell Aquatics Kalk+2 Kalkwasser Supplement, 225 grams

  • Contains calcium, strontium, and magnesium in the same ionic
    ratios found in aragonite. This unique feature increases the
    usefulness of Kalk+2 to reef-building invertebrates such as corals, clams, calcareous algae, etc
  • Provides temporary alkalinity and helps maintain pH within the
    desired range when used as directed
  • Adds no conservative elements, such as chloride, to the
    aquarium
  • Improves upon the industry-standard powdered calcium
    supplement over the past three decades
  • Formulated by a marine scientist

Our Price: $10.30
In Stock
Brightwell Aquatics Kalk+2 Kalkwasser Supplement, 450 grams Brightwell Aquatics Kalk+2 Kalkwasser Supplement, 450 grams

  • Contains calcium, strontium, and magnesium in the same ionic
    ratios found in aragonite. This unique feature increases the
    usefulness of Kalk+2 to reef-building invertebrates such as corals, clams, calcareous algae, etc
  • Provides temporary alkalinity and helps maintain pH within the
    desired range when used as directed
  • Adds no conservative elements, such as chloride, to the
    aquarium
  • Improves upon the industry-standard powdered calcium
    supplement over the past three decades
  • Formulated by a marine scientist

Our Price: $14.20
In Stock