Reef Fusion 2 — Alkalinity 4400 meq/L 2-Part System 1 L, 2 L and 4 L - Seachem

Seachem Reef Fusion 2 is an alkalinity supplement based on a concentrated blend of carbonates and bicarbonates at 4400 meq/L, designed to restore and maintain alkalinity in reef aquariums. It is part of the Reef Fusion system, the most concentrated 2-part system on the market, formulated for easy dosing in a 1:1 ratio with Seachem Reef Fusion 1 (calcium). Available in 1 L, 2 L and 4 L.

Main advantages

• Concentration of 4400 meq/L — the most concentrated 2-part system available
• Simple 1:1 dosing ratio with Reef Fusion 1
• Provides the carbonates essential for the growth of calcareous species
• Can be used separately to target alkalinity independently of calcium

Use in reef aquariums

Reef Fusion 1 and Reef Fusion 2 form a complete system to maintain the critical calcium and alkalinity levels necessary for coral growth. Reef Fusion 1 provides 100,000 mg/L of ionic calcium along with magnesium, strontium, boron, iron, manganese, and molybdenum. Reef Fusion 2 provides carbonate alkalinity at 4400 meq/L. Together, they maintain an optimal balance while supplying biologically appropriate trace elements.

Dosage

• Dose every 1 to 2 days. Shake well before use.
• Add 1 ml of Reef Fusion 1 per 25 L (6.5 US gallons) in a high-flow area. Wait a few minutes, then add 1 ml of Reef Fusion 2 per 25 L in the same way.
• Each dose provides 4 mg/L of calcium and 0.176 meq/L of alkalinity.
• Maintain calcium between 380 and 420 mg/L and alkalinity between 3 and 6 meq/L (8–17 dKH).
• Do not exceed 4 ml per 25 L per day.

Manufacturer's precautions

• Never mix Reef Fusion 1 directly with Reef Fusion 2
• Add the two products to separate locations in the aquarium
• Make significant adjustments gradually to avoid shocking corals and invertebrates

Available formats

• 1 L
• 2 L
• 4 L

Why choose Reef Fusion 2 at ReefSolution

For a complete dosing system, pair Reef Fusion 2 with Seachem Reef Fusion 1 in a 1:1 ratio — the calcium half of the same system. If you prefer powdered alkalinity, Reef Builder does the same job without immediate pH impact. Track your parameters with the Salifert KH/Alk Test Kit for precise alkalinity maintenance.

Frequently Asked Questions

Can Reef Fusion 2 be used on its own without Reef Fusion 1?

Yes. Seachem confirms that both products can be used individually to adjust calcium or alkalinity separately if your system is unbalanced.

What is the difference between Reef Fusion 2 and Reef Carbonate?

Reef Fusion 2 is designed as a 2-part system with Fusion 1 in a 1:1 ratio, concentrated at 4400 meq/L. Reef Carbonate is a standalone supplement at 4000 meq/L with a pK of 9.0 that stabilizes pH at 8.3–8.4.

How much Reef Fusion 2 should I dose per day?

1 ml per 25 L every 1 to 2 days, providing 0.176 meq/L of alkalinity per dose. Do not exceed 4 ml per 25 L per day. Adjust frequency according to your test results.