Red Sea Foundation A Calcium+ Powder 1 KG (2.2lb)

Red Sea Reef Foundation A is the calcium supplement in Red Sea's Reef Foundation ABC program. This 1 kg (2.2 lb) powder delivers calcium plus strontium and the minor elements found in coral skeletons, in the same ratio corals use to grow—an economical way to keep calcium dialed in for thriving SPS and LPS reefs.

Build the full program with more Red Sea reef care and additives & supplements at Squeaky's Aquatics.

Why Reef Foundation A

• Maintains calcium — replenishes the calcium corals consume as they build their skeletons.
• Skeleton-ratio blend — includes strontium and minor elements in the proportion found in coral skeletons.
• Part of the ABC system — works alongside Foundation B (Alkalinity) and Foundation C (Magnesium) for balanced growth.
• Economical 1 kg powder — far more dosing per dollar than pre-mixed liquids; great for larger systems.
• Make your own solution — dissolve into a stock dosing solution or add directly per the program.

Dosing & Use

• Dose to your tank's measured calcium uptake, following Red Sea's Reef Foundation program.
• Never add more than 60 g at once, regardless of tank size; space larger amounts 10 minutes apart to avoid precipitation.
• Test calcium weekly and keep Calcium, Alkalinity, and Magnesium in balance.
• For a stock solution, dissolve 1 kg into roughly 550 L (per Red Sea's Calcium+ guidelines).

Specifications

Recommended Pairings

• Red Sea Reef Foundation B (KH/Alkalinity) Powder — the alkalinity half of the program.
• Red Sea Reef Foundation C (Magnesium) Powder — keeps Ca & Alk in balance.
• Red Sea Reef Foundation Pro Multi Test Kit — test Ca, Alk & Mg to dose accurately.

FAQ

What does Foundation A do? It maintains calcium—along with strontium and minor elements—so corals have the building blocks they need for skeletal growth.

Powder vs. liquid—what's the difference? The powder is a concentrated, more economical form. You dose it per the program or dissolve it into your own stock solution.

How much should I dose? It depends on your tank's calcium uptake—test weekly and dose to demand. Never add more than 60 g at once.

Do I need all three (A, B, C)? For balanced coral growth, yes—calcium, alkalinity, and magnesium must be kept in proportion.