---
product_id: 9396800
title: "Reef Advantage Magnesium, 1.2 kg / 2.6 lbs"
brand: "seachem"
price: "C$3942"
currency: NIO
in_stock: true
reviews_count: 11
category: "Seachem"
url: https://www.desertcart.ni/products/9396800-reef-advantage-magnesium-1-2-kg-2-6-lbs
store_origin: NI
region: Nicaragua
---

# Treats 1200 US gallons per 300g No ammonia contamination 80,000 ppm concentrated blend Reef Advantage Magnesium, 1.2 kg / 2.6 lbs

**Brand:** seachem
**Price:** C$3942
**Availability:** ✅ In Stock

## Summary

> 🌟 Elevate your reef’s vitality with pure, powerful magnesium — because your aquarium deserves the best!

## Quick Answers

- **What is this?** Reef Advantage Magnesium, 1.2 kg / 2.6 lbs by seachem
- **How much does it cost?** C$3942 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.ni](https://www.desertcart.ni/products/9396800-reef-advantage-magnesium-1-2-kg-2-6-lbs)

## Best For

- seachem enthusiasts

## Why This Product

- Trusted seachem brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Pure & Clean Formula:** Free from ammonia, eliminating common contaminants found in liquid magnesium supplements.
- • **Easy, Accurate Dosing:** Simple twice-weekly dosing with clear instructions and compatibility with digital scales for precision.
- • **Balanced Ionic Support:** Maintains natural seawater ionic ratios to protect your aquatic ecosystem’s delicate balance.
- • **Economical & Efficient:** Just 300 grams treats up to 1200 gallons, delivering high value for serious reef keepers.
- • **Precision Magnesium Boost:** Restores depleted magnesium levels with a potent 80,000 ppm formula for optimal reef health.

## Overview

Reef Advantage Magnesium is a highly concentrated, ammonia-free blend of magnesium, chloride, and sulfate salts designed to restore and maintain optimal magnesium levels in saltwater aquariums. It supports stable pH and ionic balance, treats large volumes efficiently, and is trusted by reef enthusiasts to prevent magnesium depletion caused by kalkwasser and carbonate additives.

## Description

Severely depleted levels of magnesium (below 800 mg/L) can cause depressed pH levels and an inability to maintain proper magnesium levels. The most frequent causes of magnesium deficiency are use of kalkwasser, frequent overdosing of a carbonate additive, or low levels in the salt mix itself. Kalkwasser, for instance, precipitates magnesium as magnesium hydroxide while excess carbonates precipitate it as magnesium carbonate. In both cases, this means that magnesium that was present in the water is now unavailable. Of the two, magnesium hydroxide and magnesium carbonate, the former is more problematic; it is extremely insoluble. Once magnesium has precipitated as magnesium hydroxide, it will never redissolve. Magnesium carbonate will redissolve; however, it does so slowly. So, while it will go back into solution, there will be a significant portion of time in which magnesium levels are depleted.Reef Advantage Magnesium™ is a concentrated (80,000 ppm) optimized blend of magnesium, chloride, and sulfate salts designed to restore depleted levels of magnesium with minimal impact to the ionic ratios found in natural sea water. Reef Advantage Magnesium™ contains no ammonia. This is a common contaminant in every liquid magnesium supplement on the market.

Review: Works🤷🏽‍♂️like it should - Works to bring magnesium up, easy to use
Review: Cheap good aquarium Magnesium - Did you accidentally fill your aquarium with regular water softener salt, and later realize that Magnesium is very important in saltwater? Cheapest way to bring that bad boy right back up.

## Features

- Raises magnesium and contains no ammonia
- A concentrated optimized blend of magnesium, chloride, and sulfate salts designed to restore depleted levels of magnesium
- Minimal impact to the ionic ratios found in natural sea water
- Contains no ammonia, a common contaminant in every liquid magnesium supplement on the market
- 300 grams treats 1200 US gallons

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B001F0MMBO |
| ASIN  | B001F0MMBO |
| Age Range Description | all stages |
| Best Sellers Rank | #153,658 in Health & Household ( See Top 100 in Health & Household ) #2,027 in Magnesium Mineral Supplements |
| Brand Name | Seachem |
| Color | white |
| Customer Reviews | 4.6 4.6 out of 5 stars (159) |
| Date First Available | August 28, 2008 |
| Date First Available  | August 28, 2008 |
| Directions | Use 5 g (1 level teaspoon) per 80 L (20 gallons) twice a week. Dissolve in at least 250 mL (1 cup) of freshwater. For precise dosing, use the Seachem Digital Spoon Scale. |
| Included Components | all |
| Is Discontinued By Manufacturer  | No |
| Item Dimensions LxWxH | 3.75 x 3.75 x 7.75 inches |
| Item Package Dimensions L x W x H | 8.03 x 3.7 x 3.7 inches |
| Item Weight | 2.4 Pounds |
| Item model number | 637 |
| Item model number  | 637 |
| Manufacturer | Seachem Laboratories, Inc. |
| Manufacturer  | Seachem Laboratories, Inc. |
| Model Name | Reef Advantage Magnesium 1.2 kg |
| Number of Items | 1 |
| Product Dimensions  | 3.75 x 3.75 x 7.75 inches; 2.44 Pounds |
| Size | 1.2 kg / 2.6 lbs |
| Specific Uses for Product | Active |
| Target Audience Keyword | fish;algae-eaters; betta-fish; bottom-feeder-fish; cichlid-fish; goldfish; invertebrate-fish; mollusks; octopuses; rays; sharks; snails |

## Product Details

- **Brand:** Seachem
- **Item Form:** Tablets
- **Item Weight:** 2.4 Pounds
- **Liquid Volume:** 250 Milliliters
- **Manufacturer:** Seachem Laboratories, Inc.

## Images

![Reef Advantage Magnesium, 1.2 kg / 2.6 lbs - Image 1](https://m.media-amazon.com/images/I/816lzqkEJKL.jpg)

## Questions & Answers

**Q: is this something I can use for my hydroponics system?  (vs. Epson Salt)**
A: It’s the same basic thing as epsom salt, just without any anti-caking agents in it.

**Q: Is this safe for freshwater planted tanks?  My calcium is much higher then magnesium and would like to increase it.**
A: Honestly, I'm not sure.  I'm a salt water guy, but I do know that you should not add buffers of any kind unless you know that they are needed. If you know what the Magnesium levels are supposed to be, you could probably use this product to correct your Mag levels, but I wouldn't do anything unless I spoke to someone at my local fish store.  Be careful!

**Q: Is it supposed to have bigger chunks in the container?**
A: There’s no anti-caking agents in it so clumps can happen. Just shake the container to break up the clumps.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Works🤷🏽‍♂️like it should
*by E***D on November 8, 2025*

Works to bring magnesium up, easy to use

### ⭐⭐⭐⭐⭐ Cheap good aquarium Magnesium
*by K***E on October 27, 2023*

Did you accidentally fill your aquarium with regular water softener salt, and later realize that Magnesium is very important in saltwater? Cheapest way to bring that bad boy right back up.

### ⭐⭐⭐⭐⭐ SeaChem is the best!
*by T***Y on April 14, 2015*

I have had a reef tank for about three years now and the SeaChem products is all I ever dose with. They dissolve easy and are a great price. They are also made right in Georgia so it is a Made in USA product which is great.

## Frequently Bought Together

- Seachem Reef Advantage Magnesium, 1.2 kg
- Seachem Reef Advantage Calcium, 500 g

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*Product available on Desertcart Nicaragua*
*Store origin: NI*
*Last updated: 2026-03-10*