Seachem Reef Aquarium Alkalinity Supplement, 4 L, Concentrated Reef Fusion 2

Seachem Reef Fusion 2 is a reef aquarium alkalinity supplement designed to restore and maintain alkalinity, with a 4400 meq/L alkalinity concentration in a 4 L / 1 fl. gal. size.

• Designed to restore and maintain reef aquarium alkalinity — supports stable aquarium alkalinity levels.
• 4400 meq/L alkalinity — provides concentrated alkalinity in the Reef Fusion two-part system.
• Simple 1:1 pairing with Reef Fusion 1 — makes the two-part system straightforward to use together.
• Identified as the most concentrated two-part system — combines the two supplements in a simple ratio.
• 4 L / 1 fl. gal. bottle — provides Reef Fusion 2 for reef aquarium use.

Reef aquariums need alkalinity as part of the water chemistry that supports coral growth. Reef Fusion 2 is the alkalinity component of Seachem’s two-part Reef Fusion system, made for aquarists who want to restore or maintain this essential parameter. Its role is distinct from Reef Fusion 1, which supplies calcium, so the two products work as a coordinated system rather than interchangeable supplements.

What does Seachem Reef Fusion 2 do in a reef aquarium?

Seachem Reef Fusion 2 supplies a mixture of carbonates and bicarbonates to restore and maintain alkalinity. The carbonate it provides is essential for the growth of calcareous species, including corals. This makes the product’s purpose specifically relevant to reef aquariums where maintaining alkalinity is part of supporting coral growth.

• Carbonates and bicarbonates form the alkalinity mixture.
• Calcareous species receive the essential carbonate needed for growth.

How does Reef Fusion 2 work with Reef Fusion 1?

Use the two products together as the Reef Fusion system: Reef Fusion 1 provides calcium, while Reef Fusion 2 provides alkalinity. When used as directed, the pair maintains the critical calcium and alkalinity levels necessary for healthy coral growth, while providing biologically appropriate levels of other elements and trace minerals. Reef Fusion 1 provides 100,000 mg/L of ionic calcium; that calcium specification belongs to Reef Fusion 1, not Reef Fusion 2.

• Reef Fusion 1 is the calcium component of the system.
• The paired system is designed to maintain calcium and alkalinity together.

Who is the 4 L Reef Fusion 2 bottle made for?

This bottle is for reef aquarium keepers using Reef Fusion 2 as the alkalinity part of the Reef Fusion system. The stated package size is 4 L / 1 fl. gal. The product is intended for reef aquarium alkalinity management, with particular relevance to aquariums containing calcareous species that need carbonate for growth. Pair it with Reef Fusion 1 in the system’s simple 1:1 ratio; Reef Fusion 2 alone is the alkalinity component, not the source of the system’s calcium.

• Designed for reef aquarium use.
• Pairs with Reef Fusion 1 in a 1:1 ratio.

Seachem Reef Fusion 2 best suits reef aquarists managing alkalinity as part of a two-part approach, especially those keeping corals and other calcareous species. Its defined role is to provide carbonate-based alkalinity, while Reef Fusion 1 supplies calcium. For buyers seeking the alkalinity component in the Reef Fusion system, this 4 L bottle delivers that specific function.