Foundation A Calcium+ 1kg — Calcium, Strontium and Barium Powder - Red Sea

Foundation A Calcium+ powder from Red Sea holds the same elements as the liquid version — calcium, strontium and barium in the ratios of coral skeleton — in dry form. 1kg bag.

Powder and liquid do not dose the same

Powder is not dosed like liquid, and that is where most mistakes happen. Two figures to keep straight:

• Dry powder: 1g raises calcium in 100 litres (25 gal) by 3.6ppm
• Ready-to-use liquid: 1ml raises calcium in 100 litres by 2ppm

In other words, a gram of powder does nearly twice the work of a millilitre of liquid. Never carry a calculation from one format to the other.

Making your stock solution

Dry powder does not go through a dosing pump as-is: it has to be dissolved first. Red Sea publishes the recipe: 550g of powder per litre of RO water, which means a 1kg bag yields 1.8 litres of stock solution. That solution then doses exactly like the shelf liquid: 1ml per 100 litres raises calcium by 2ppm.

That is the appeal of the format: one 1kg bag replaces nearly two litres of liquid product, without paying to ship water.

Specifications

• Elements: calcium, strontium and barium
• Powder concentration: 1g raises calcium in 100 litres (25 gal) by 3.6ppm
• Stock solution: 550g per litre · 1kg yields 1.8L
• Daily maximum: 20ppm of calcium per day
• Sizes: 250ml, 500ml, 1L, 5L liquid · 1kg powder (this listing)
• Suitable for: SPS, LPS and soft coral reef tanks

Powder concentration figures come from CoralVue, Red Sea's official North American distributor, and match the stock solution table in Red Sea's Foundation manual.

Target levels for your reef tank

Three rules not to skip

• Daily maximums: calcium 20ppm, alkalinity 0.5 meq/l (1.4 dKH), magnesium 10ppm.
• Dosing order: magnesium, then alkalinity, then calcium — 10 minutes between each.
• Where to add it: into the sump, or slowly into a high-flow area.

Adding calcium to saturation levels causes a sudden drop in alkalinity. The three elements hold each other up.

Goes well with

Calcium does not work alone. The other two powders complete the trio: Foundation B KH/Alkalinity 1kg for the carbonates and Foundation C Magnesium 1kg to keep the two from precipitating against each other.

If mixing stock solutions is not your thing, Foundation A Calcium+ 1L is ready to dose as-is.

Frequently asked questions

What is the difference between powder and liquid?

Same elements, different strength: 1g of powder raises calcium by 3.6ppm per 100L against 2ppm for 1ml of liquid. Powder costs less for the equivalent volume since you are not shipping water, but it takes preparation.

Can I add the powder straight to the tank?

Red Sea publishes a stock solution recipe (550g/L) precisely so you do not have to. Dissolving first is also the only way to use a dosing pump.

How much solution does a 1kg bag make?

1.8 litres of stock solution, dosed afterwards like the Red Sea liquid: 1ml per 100 litres raises calcium by 2ppm.

How much calcium can I add in one day?

20ppm at most, per Red Sea. Beyond that, spread it over several days.

Why buy from ReefSolution

Aquarium ReefSolution is an authorized Red Sea dealer. Our team works in marine aquariums in Laval and knows the Reef Care Program from real tanks. We ship across Canada and offer in-store pickup.