Seachem Reef Fusion 1 500 mL – Concentrated Reef Calcium Supplement
Seachem Reef Fusion 1 500 mL is the concentrated calcium component of Seachem’s two-part Reef Fusion dosing system. It supplies 100,000 mg/L of ionic calcium along with biologically appropriate amounts of magnesium, strontium, boron, iron, manganese, molybdenum, and rubidium.
When paired with Seachem Reef Fusion 2, Reef Fusion 1 helps maintain the calcium and alkalinity levels required by stony corals, coralline algae, clams, and other calcifying reef organisms. The two-part system uses a simple 1:1 dosing ratio, making it convenient for routine reef aquarium maintenance.
The 500 mL bottle is an excellent choice for nano to medium reef aquariums, mixed reef systems, and hobbyists beginning a two-part calcium and alkalinity dosing routine.
Key Features
- Highly Concentrated Calcium: Provides 100,000 mg/L of ionic calcium
- Part One of a Two-Part System: Designed for use with Seachem Reef Fusion 2
- Simple 1:1 Dosing Ratio: Dose equal amounts of Reef Fusion 1 and Reef Fusion 2 for balanced supplementation
- Includes Supporting Elements: Contains magnesium, strontium, boron, iron, manganese, molybdenum, and rubidium
- Supports Calcification: Helps provide calcium used by stony corals, coralline algae, clams, and other reef-building organisms
- Flexible Dosing: May be used with Reef Fusion 2 or separately when correcting an imbalanced calcium level
- Convenient Liquid Formula: Easy to measure manually or dispense with a dosing pump
- 500 mL Bottle: Suitable for nano, small, and medium reef aquarium systems
Product Information
- Brand: Seachem
- Product: Reef Fusion 1
- Size: 500 mL
- Equivalent Size: Approximately 17 fl oz
- Product Type: Concentrated reef aquarium calcium supplement
- System: Part one of the Seachem Reef Fusion two-part system
- Calcium Concentration: 100,000 mg/L ionic calcium
- Aquarium Type: Saltwater and reef aquariums
- Standard Dosage: 1 mL per 6.5 US gallons every one to two days
- Recommended Calcium Range: 380–420 mg/L
Included Elements
- Calcium
- Magnesium
- Strontium
- Boron
- Iron
- Manganese
- Molybdenum
- Rubidium
Best Used For
- SPS coral aquariums
- LPS coral aquariums
- Mixed reef systems
- Reef aquariums with growing coral colonies
- Systems with coralline algae growth
- Marine aquariums containing clams or other calcifying invertebrates
- Nano and medium reef aquariums
- Manual two-part dosing
- Automated aquarium dosing pumps
- Correcting low calcium independently from alkalinity
Directions for Use
Shake Seachem Reef Fusion 1 well before use. Add 1 mL for every 6.5 US gallons of aquarium water every one to two days.
Add Reef Fusion 1 to an area of strong water movement so it disperses rapidly throughout the aquarium. Wait several minutes, then add the same amount of Reef Fusion 2 in the same manner.
Whenever practical, add Reef Fusion 1 and Reef Fusion 2 in separate high-flow locations. Never combine the concentrated liquids in the same dosing container, measuring cup, or reservoir.
Approximate Standard Dosage Guide
- 5-Gallon Aquarium: Approximately 0.8 mL
- 10-Gallon Aquarium: Approximately 1.5 mL
- 20-Gallon Aquarium: Approximately 3.1 mL
- 30-Gallon Aquarium: Approximately 4.6 mL
- 40-Gallon Aquarium: Approximately 6.2 mL
- 55-Gallon Aquarium: Approximately 8.5 mL
- 75-Gallon Aquarium: Approximately 11.5 mL
- 100-Gallon Aquarium: Approximately 15.4 mL
- 125-Gallon Aquarium: Approximately 19.2 mL
- 150-Gallon Aquarium: Approximately 23.1 mL
These amounts are proportional calculations based on the standard dose of 1 mL per 6.5 gallons. Calculate dosing from the aquarium’s estimated actual water volume after accounting for rock, sand, decorations, and equipment displacement.
How Much Does the Standard Dose Add?
When Reef Fusion 1 is used at the standard dose of 1 mL per 6.5 gallons, it contributes approximately 4 mg/L of calcium.
When the matching standard dose of Reef Fusion 2 is added, it contributes approximately 0.176 meq/L of alkalinity. Using both components in equal quantities helps replace calcium and carbonate alkalinity consumed by calcifying reef organisms.
Recommended Calcium Level
Seachem recommends maintaining reef aquarium calcium between approximately 380 and 420 mg/L. Test calcium regularly and adjust the amount or frequency of Reef Fusion 1 according to measured consumption.
A reef aquarium’s calcium demand can change as corals grow, new livestock is added, lighting changes, or calcification rates increase. Avoid assuming that one fixed dose will remain appropriate indefinitely.
Using Reef Fusion 1 with Reef Fusion 2
Reef Fusion 1 supplies calcium and supporting elements. Reef Fusion 2 supplies carbonate and bicarbonate alkalinity. Together, they form a complete two-part system for maintaining the two major components consumed during reef calcification.
The products are designed to be dosed in a 1:1 ratio when calcium and alkalinity are being consumed proportionally. For example, if the aquarium receives 5 mL of Reef Fusion 1, it would normally also receive 5 mL of Reef Fusion 2.
Wait several minutes between components and add them separately to high-flow areas. Never pour the concentrated products together because calcium and carbonate can react and form an insoluble precipitate.
Can Reef Fusion 1 Be Used Separately?
Yes. Reef Fusion 1 and Reef Fusion 2 may be used separately when the aquarium’s calcium and alkalinity levels are imbalanced.
For example, if calcium is below the desired range while alkalinity is already correct, Reef Fusion 1 may be dosed independently to raise calcium. Once the levels are balanced, equal dosing may resume based on the aquarium’s ongoing consumption.
Test both calcium and alkalinity before making separate corrections. Adding equal amounts to an already imbalanced aquarium may move one parameter outside the desired range.
Maximum Daily Dose
Do not exceed 4 mL of Reef Fusion 1 per 6.5 gallons in a single day.
Large calcium adjustments should be made gradually. Rapid changes can stress corals and other reef invertebrates and may increase the chance of overshooting the desired calcium level.
Using Reef Fusion with a Dosing Pump
Reef Fusion 1 and Reef Fusion 2 may be dispensed with separate dosing-pump channels. Each component must have its own tubing, reservoir, and dosing head.
Program the pump to dose the two parts at different times or into separate high-flow locations. This reduces the likelihood of the concentrated products contacting each other before they disperse.
Divide the aquarium’s required daily dose into several smaller additions when practical. Smaller doses can improve parameter stability in reef systems with high calcium and alkalinity consumption.
Manual Dosing Tips
- Shake Reef Fusion 1 before each use
- Test calcium and alkalinity before beginning a dosing routine
- Calculate dosage using actual aquarium water volume
- Add the product to a strong-flow area
- Wait several minutes before adding Reef Fusion 2
- Use separate measuring tools for each component
- Never mix Reef Fusion 1 and Reef Fusion 2 directly
- Make large corrections gradually
- Keep a dosing and testing log
- Recalculate demand as coral growth increases
Signs of Low Calcium
- Reduced skeletal growth in stony corals
- Slow coralline algae development
- Declining calcium test results between water changes
- Difficulty maintaining stable calcium in a heavily stocked reef
- Increasing calcium demand as coral colonies grow
Visual symptoms alone cannot confirm low calcium. Test calcium with a reliable marine aquarium test kit before changing the dosage.
Understanding Calcium & Alkalinity Balance
Calcium and carbonate alkalinity are both consumed when corals and other calcifying organisms build calcium carbonate skeletons. If either parameter becomes deficient, calcification and reef growth may be limited.
Calcium and alkalinity also interact chemically. Adding excessive calcium may contribute to alkalinity precipitation, while excessive alkalinity may reduce available calcium. Balanced testing and dosing are more effective than adjusting one parameter without monitoring the other.
Supporting Elements in Reef Fusion 1
In addition to calcium, Reef Fusion 1 contains biologically appropriate amounts of magnesium, strontium, boron, iron, manganese, molybdenum, and rubidium.
These elements are included as part of the complete Reef Fusion system. Reef Fusion 1 should not automatically replace dedicated magnesium or trace-element supplementation when testing shows that a separate correction is required.
Important Reef Aquarium Note
Reef Fusion 1 is a concentrated calcium supplement and is not a complete salt mix, water conditioner, coral food, or replacement for regular water changes.
Healthy coral growth also depends on stable salinity, temperature, alkalinity, magnesium, nutrients, lighting, water flow, and overall aquarium maturity.
Test calcium and alkalinity regularly. Heavily stocked SPS aquariums may require daily dosing, while lightly stocked or newer systems may require significantly less.
Do not increase dosing solely because coral growth or coloration appears poor. Similar symptoms may be caused by unstable alkalinity, inadequate lighting, low nutrients, excessive nutrients, pests, disease, or improper water flow.
Frequently Asked Questions
What is Seachem Reef Fusion 1 used for?
Reef Fusion 1 supplies concentrated ionic calcium and supporting elements for saltwater reef aquariums.
Is Reef Fusion 1 calcium or alkalinity?
Reef Fusion 1 is the calcium component. Reef Fusion 2 is the alkalinity component.
How concentrated is Reef Fusion 1?
It contains 100,000 mg/L of ionic calcium.
How much Reef Fusion 1 should I dose?
Use 1 mL for every 6.5 US gallons every one to two days, then adjust according to testing and aquarium demand.
How much calcium does the standard dose add?
The standard dose raises calcium by approximately 4 mg/L.
Should Reef Fusion 1 and 2 be dosed equally?
They are designed for a 1:1 dosing ratio when calcium and alkalinity are being consumed evenly.
Can Reef Fusion 1 be used without Reef Fusion 2?
Yes. It may be used independently when calcium is low but alkalinity is already within the desired range.
Can Reef Fusion 1 and 2 be mixed together?
No. Never mix the concentrated products directly. Add them separately and wait several minutes between doses.
Where should Reef Fusion 1 be added?
Add it to a high-flow area of the aquarium so it disperses quickly.
What calcium level should I maintain?
Seachem recommends maintaining calcium between approximately 380 and 420 mg/L.
What is the maximum daily dose?
Do not exceed 4 mL per 6.5 gallons in one day.
Does Reef Fusion 1 contain magnesium?
Yes. It contains magnesium along with strontium, boron, iron, manganese, molybdenum, and rubidium.
Can Reef Fusion 1 be used with a dosing pump?
Yes. Use a dedicated pump channel and separate tubing from Reef Fusion 2.
Is Reef Fusion 1 safe for reef aquariums?
Yes. It is formulated specifically for reef aquariums and calcifying marine organisms when used according to the directions.
Does Reef Fusion 1 replace water changes?
No. It supplements calcium and supporting elements but does not replace regular water changes or complete reef maintenance.
Available at Tropical Treasures Wyo
Seachem Reef Fusion 1 500 mL provides highly concentrated ionic calcium and supporting elements for coral growth and balanced reef aquarium chemistry. Pair it with Seachem Reef Fusion 2 for a complete two-part calcium and alkalinity dosing system.
Visit Tropical Treasures Wyo in Cheyenne, Wyoming, to shop Seachem reef supplements, calcium and alkalinity test kits, dosing pumps, marine filtration, coral foods, and saltwater aquarium care essentials.
Explore More Aquarium Products:
Low stock: 2 left
Couldn't load pickup availability
Explore Related Aquarium Products: