ESV Aquatics B-Ionic Calcium Buffer System, 3.8 L 2-Pack for Reef Aquariums

ESV Aquatics B-Ionic Calcium Buffer System is a two-part liquid supplement for maintaining calcium and alkalinity in saltwater aquariums, supplied as two concentrated 1-gallon (3.785 L) bottles.

• Two liquid components used in equal volumes — supports aquarium maintenance without mixing powders.
• Concentrated calcium and carbonate alkalinity — supplies elements required for calcification.
• Major, minor, and trace elements in ratios that match natural seawater — supports the aquarium’s ionic balance.
• No phosphates, nitrates, or added organic chemicals — keeps these substances out of the supplement system.
• Two 1-gallon bottles, Parts A and B, that must be diluted before use — provides a concentrated format for saltwater aquarium care.

Reef aquariums rely on suitable calcium and alkalinity levels for calcification, and aquarium maintenance can also involve replacing inorganic ions lost through protein skimming. B-Ionic is made for aquarists who want a liquid, two-component approach to maintaining aquarium water. Its paired components provide calcium and carbonate alkalinity alongside other elements, rather than requiring the aquarist to prepare separate powder mixtures.

What does B-Ionic help maintain in a reef aquarium?

It is formulated to help maintain calcium and alkalinity levels and support the calcification process in saltwater aquariums. The concentrated components supply calcium and carbonate alkalinity, together with major, minor, and trace elements in ratios intended to duplicate natural seawater. Used as a maintenance supplement, the system also helps restore inorganic ions lost from protein skimming and maintain the aquarium’s ionic balance.

• The formulation contains no phosphates or nitrates.
• It does not add organic chemicals to the aquarium.
• The system is an alternative to a calcium reactor.

How do I prepare and dose the two components?

Dilute the concentrated bottles with RO/DI water or distilled water before use, then use equal volumes of Part A and Part B. The starting daily dosage is 1 ml per 4 gallons (15.1 L) of aquarium capacity. This is a starting dosage for aquarium maintenance; the product is a concentrate, not a ready-to-use liquid.

• Use the same volume of each component.
• Both components require dilution before use.
• The starting dosage is based on aquarium capacity.

What comes in the pack?

The pack contains two 1-gallon bottles: one bottle of Part A and one bottle of Part B. Together, the two liquids make up the B-Ionic Calcium Buffer System; the paired components are intended to be used in equal volumes. Their concentrated format means dilution with RO/DI or distilled water is part of preparation before aquarium use.

• Quantity: two bottles.
• Contents: Part A and Part B.
• Each bottle holds 1 gallon (3.785 L).

How does the system support coral aquarium care?

B-Ionic supplies calcium and carbonate alkalinity for calcification, along with other elements in ratios based on natural seawater composition. The manufacturer’s stated purpose for the system also includes helping coral grow and thrive and improving color in saltwater aquariums; these are intended benefits, not guaranteed results. Its two-liquid format provides an alternative to powder-based supplementation and to a calcium reactor.

• Supports replenishment of inorganic ions lost through protein skimming.
• Uses two components rather than a single liquid component.
• Provides calcium, carbonate alkalinity, and other major, minor, and trace elements together.

This system suits saltwater reef aquarists who want a concentrated, two-part liquid supplement for ongoing calcium and alkalinity maintenance, and who can dilute the components before use. It is designed for saltwater aquarium care, with its paired bottles supplying the components in equal volumes.

Read our guide: A beginner’s aquarium set-up checklist: from bowl to tank