Seachem Reef Advantage Magnesium 600 gm

Reef Advantage Magnesium is a concentrated (80,000 ppm) optimized blend of magnesium, chloride, and salts designed to restore depleted levels of magnesium with minimal impact to the ionic ratios found in natural sea water.

Compatibility

What it is. A concentrated (80,000 ppm) blend of magnesium, chloride and sulfate salts, built to restore depleted magnesium without disturbing the other ionic ratios in the tank. Seachem notes it carries no ammonia, which it flags as a common contaminant in other magnesium supplements on the market.

Why magnesium matters here. Seachem’s own note: severely depleted magnesium (below 800 mg/L) makes it hard to hold pH and keep calcium/alkalinity stable at all, no matter how much calcium or buffer gets dosed. The usual causes are kalkwasser use, over-dosing a carbonate additive, or a salt mix that starts low.

Dosage & Directions

Seachem’s own dose (beginner). 5 g (1 level teaspoon) per 80 L (20 US gallons), twice a week, dissolved in at least 250 ml of fresh water before adding.

Advanced dosing. Each 5 g/80 L raises magnesium by about 5 mg/L; test with a magnesium kit and dose to Seachem’s target range of 1,200 to 1,350 mg/L. Don’t exceed 25 g/80 L per day.

Continuous drip. Seachem’s own formula for a dosing pump: g = (v × m)/80, where v is tank volume in litres and m is the desired magnesium increase in mg/L.

Keep it away from carbonate additives, and go slow. Don’t mix directly with a carbonate supplement: dose at least 30 minutes apart, or on alternate days. Excess magnesium can itself erode carbonate alkalinity, so make large corrections gradually rather than in one dose.

Freshness & Storage

Every batch we dispatch carries a minimum of 6 months’ remaining shelf life. Store this product in a cool, dry place away from direct sunlight, with the cap or inner foil closed tightly after each use.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number, or email us if you would rather, and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 48 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.