Brightwell Aquatics

400g Calcion-P - Dry Calcium Reef Additive

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$16.15 $17.95

Discontinued by Bulk Reef Supply
- +

Brightwell’s CalcION-P is part of a complete system for maintaining the major elements. The concentrated powder form is perfect for those who want to mix their own solutions at home for dosing by hand or with a dosing pump, and when coupled with Alkalin8.3-P and MagnesION-P, it is convenient and economical to maintain stable levels of each of these critical components.



  • High-purity powdered calcium.
  • Increases the concentration of calcium in marine aquarium water to provide 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 large reef systems.


Available in Two Sizes

  • 400 grams
  • 800 grams


Instructions and Guidelines

Basic: Dissolve 2 grams (~½ teaspoon) of product per 20 US-gallons of aquarium water in 8-fl. oz. of fresh water; add every other day or as needed to maintain the calcium concentration within a range of 412 - 450 ppm. When used in this fashion, 800 g treats up to 8,000 US-gallons (30,283 L).



Always try to maintain the [Ca2+] within a range of +/-10 ppm. Daily dosing maintains a more stable calcium concentration (and more natural environment) than dosing weekly, in which the calcium spikes just after dosing and then gradually decreases throughout the course of the week. 

Each ml of the solution will increase the calcium concentration in 1 US-gallon (3.785 L) of water by 2.50 ppm. [Reference: Each g of Calcion-P will increase the calcium in 1 US-gallon (3.785 L) of water by 95 ppm.]

  • If the initial [Ca2+] in the aquarium is below 412 ppm, add this product at the maximum rate of 10 ml per 20 US-gallons daily until the desired calcium concentration is attained.
  • Thereafter, dose daily or weekly as needed (see below). 
  • To determine the consumption rate of calcium in your system, measure the daily rate of calcium uptake (i.e. the decrease in calcium) in your aquarium by measuring the calcium level at the same time each day over a one-to-two-week period.
  • To determine the daily dosing rate (preferred over weekly dosing) for calcium maintenance: estimate the volume of water in the entire aquarium system; divide the daily decrease in calcium by 2.5; then multiply this number by the volume of water in the system to get the daily dosage required (in ml) to maintain calcium. 


Caution: Keep out of reach of children. Not for human consumption.


Guaranteed Analysis

  • Calcium (min - max) 33 - 37% (330,000 - 370,000 ppm)
More Information
UPC 810086011049
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