Magnesium 4 kg — Bulk Stable Magnesium for Reef Aquariums - Aquaforest

Aquaforest Magnesium 4 kg — stable magnesium large format for reef aquariums

The Aquaforest Magnesium 4 kg ships purified magnesium chloride powder in an economy large format. Used in the classic Balling protocol to prepare the magnesium stock solution (Part 3), it holds the Ca/Mg ratio stable — critical to blocking abiotic precipitation and keeping coral biomineralization steady. Format aimed at established tanks with sustained consumption and multi-tank setups.

The 4 kg bucket makes several months to several years of stock solution depending on system consumption. Same recipe as the 750 g jar — only quantity changes.

Large-format Balling use

• Stock solution: 25 g of Magnesium per liter of RO/DI water, paired with Reef Mineral Salt for trace elements (K, I, Br, F).
• Component K Strong: 5 ml per liter of solution for advanced Balling.
• Balanced dosing: equal shares with Calcium and KH Buffer.
• Storage caution: keep dry — magnesium chloride is very hygroscopic.

Mg targets

• Reef magnesium: 1,180-1,460 ppm (aim 1,300-1,400).
• Ca/Mg ratio: ~3.2 (Ca 420 ppm / Mg 1,350 ppm for example).
• Never below 1,150 ppm — fast KH-Ca stability degradation.

Specifications

• Brand: Aquaforest (Poland)
• Format: 4 kg powder bucket
• Type: large-format magnesium chloride
• Compatibility: established reef tanks, advanced setups, frag farms

Why choose Aquaforest at ReefSolution

• Magnesium 750 g — the trial format before large-bucket commitment.
• Calcium 3.5 kg — Balling Part 1 in the matching large format.
• KH Buffer 5 kg — Balling Part 2 large format that completes the powder trio.

Frequently asked questions

How long does a 4 kg bucket last on a 400 L tank?

On a 400 L tank with moderate SPS/LPS consumption (about 150-250 g of Magnesium per month), the 4 kg bucket covers 16 to 26 months. On a high-growth SPS tank with sustained draw (400 g/month), duration drops to 10 months.

Can I prepare a more concentrated stock solution?

Yes — Aquaforest notes that Mg solution concentration can be doubled or tripled for low-evaporation tanks, within the magnesium chloride solubility limit. A 50-75 g/L solution stays stable if the RO/DI water is warm during prep.

How should I store the opened 4 kg bucket?

Reseal the lid carefully after each draw and store in a dry location. Magnesium chloride can turn to paste on contact with humidity — a desiccant packet inside or a gasketed lid preserves the powder for a long time.