Hover to zoom
Seachem Reef Fusion 1 and 2
Balanced two-part dosing for calcium and alkalinity
- Two-part system supplies calcium and alkalinity for corals
- Reef Fusion 1 delivers calcium and trace elements
- Reef Fusion 2 provides carbonate alkalinity and more
- Designed to keep parameters balanced as corals consume them
- Supports growth in stony corals and clams
Check the latest price and availability on Amazon.
View on Amazon →As an Amazon Associate, AquaticRig earns from qualifying purchases.
Pros
- Maintains calcium and alkalinity together for stability
- Includes supporting trace elements, not just the basics
- Scales easily as coral demand grows
- Consistent Seachem chemistry and quality
- Flexible dosing to match your tank's uptake
Cons
- Two bottles to manage and dose separately
- Requires regular testing to dose correctly
- Heavy-demand tanks may prefer a calcium reactor long term
- Marine reef use only
At a glance
Balanced two-part dosing for calcium and alkalinity
Seachem Reef Fusion 1 and 2 keeps calcium and alkalinity in balance as your corals draw them down, which is the foundation of healthy reef growth.
- Two-part system supplies calcium and alkalinity for corals
- Reef Fusion 1 delivers calcium and trace elements
- Reef Fusion 2 provides carbonate alkalinity and more
- Designed to keep parameters balanced as corals consume them
- Supports growth in stony corals and clams
Product Specifications
- Type
- Two-part supplement
- Part 1
- Calcium and trace elements
- Part 2
- Alkalinity and carbonates
- Use
- Reef tanks with corals
- Water type
- Saltwater reef
- Dosing
- Test-guided, adjustable
Why we recommend the Seachem Reef Fusion 1 and 2
Growing corals steadily consume calcium and alkalinity, and keeping those two parameters in balance is one of the central tasks of reef keeping. Let either drift and coral health suffers. Reef Fusion is Seachem’s two-part answer: Part 1 supplies calcium along with supporting trace elements, while Part 2 delivers carbonate alkalinity. Dosed together against your test results, they replenish what your corals use and hold the system stable.
The inclusion of trace elements beyond the headline calcium and alkalinity is a nice touch, giving corals a fuller spectrum of what they need rather than just the two big numbers. The system is flexible, too. As your reef matures and demand climbs, you simply scale the dosing to match uptake, which makes it suitable for everything from a young soft-coral tank to a growing collection of stony corals and clams.
Who it’s for
This is for reef keepers maintaining calcium-hungry corals who want a reliable, balanced two-part dosing system. It rewards a testing habit, since accurate dosing depends on knowing your current parameters, and it does mean keeping two bottles in rotation. Very high-demand systems may eventually graduate to a calcium reactor, but for most reef tanks Reef Fusion is a flexible, quality way to keep the foundation parameters where they belong.
The Bottom Line
Seachem Reef Fusion 1 and 2 keeps calcium and alkalinity in balance as your corals draw them down, which is the foundation of healthy reef growth. It asks for regular testing and two bottles to manage, but it scales nicely with your tank's demand.
View on Amazon →As an Amazon Associate, AquaticRig earns from qualifying purchases.
Frequently Asked Questions
What is the difference between Part 1 and Part 2?
Part 1 supplies calcium and trace elements, while Part 2 provides carbonate alkalinity. Used together, they keep both key parameters balanced for coral growth.
Do I need to test before dosing?
Yes. Accurate two-part dosing depends on knowing your current calcium and alkalinity, so regular testing is essential to dose the right amounts.
Can I scale it as my reef grows?
Absolutely. The system is flexible, so you increase dosing to match rising coral demand as your tank matures and consumes more.
Is this better than a calcium reactor?
Two-part is simpler to start and ideal for most tanks. Very high-demand systems sometimes move to a calcium reactor for hands-off bulk supplementation.
Is it only for saltwater?
Yes. Reef Fusion is a marine reef supplement for calcium and alkalinity. It has no role in freshwater aquariums.