{"product_id":"seachem-reef-advantage-magnesium","title":"Seachem Reef Advantage Magnesium","description":"\u003cp\u003e\u003cstrong\u003eSeachem Reef Advantage Magnesium\u003c\/strong\u003e is a concentrated blend of magnesium, chloride, and sulfate salts that restores depleted magnesium while keeping ionic ratios close to natural seawater. Magnesium is the element that lets you hold calcium and alkalinity at the same time, so when it runs low your reef numbers get hard to control and pH can sag. Unlike many liquid magnesium supplements, this one contains no ammonia. Browse our full range of \u003ca href=\"https:\/\/squeakysaquatics.com\/collections\/additives-supplements\"\u003ereef additives and supplements\u003c\/a\u003e and the rest of the \u003ca href=\"https:\/\/squeakysaquatics.com\/collections\/seachem\"\u003eSeachem lineup\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3 style=\"margin: 16px 0 4px; font-size: 1.05em; font-weight: 600; line-height: 1.25; border-left: 4px solid #006064; padding-left: 8px;\"\u003eWhy Reefers Use It\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eKeeps calcium and alkalinity in balance.\u003c\/strong\u003e Proper magnesium is what lets both stay where you want them.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo ammonia.\u003c\/strong\u003e A common contaminant in liquid magnesium supplements, left out here.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNatural ratios.\u003c\/strong\u003e Restores magnesium with minimal impact to the other ions in your saltwater.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixes the usual culprits.\u003c\/strong\u003e Counters magnesium loss from kalkwasser, heavy carbonate dosing, or a low-magnesium salt mix.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin: 16px 0 4px; font-size: 1.05em; font-weight: 600; line-height: 1.25; border-left: 4px solid #006064; padding-left: 8px;\"\u003eHow to Use\u003c\/h3\u003e\n\u003cp\u003eDissolve 5 g (1 level teaspoon) in at least 250 mL (1 cup) of fresh water, then add it to the tank for every 80 litres (about 20 US gallons), twice a week. Each dose raises magnesium by roughly 5 mg\/L. Do not exceed 25 g per 80 L per day, since too much magnesium can pull down carbonate alkalinity. Test magnesium regularly and adjust. Do not mix Reef Advantage Magnesium directly with a carbonate or alkalinity supplement; add them on alternate days or at least 30 minutes apart.\u003c\/p\u003e\n\u003ch3 style=\"margin: 16px 0 4px; font-size: 1.05em; font-weight: 600; line-height: 1.25; border-left: 4px solid #006064; padding-left: 8px;\"\u003eChoose Your Size\u003c\/h3\u003e\n\u003ctable style=\"border-collapse: collapse; width: 100%; font-size: 0.95em; margin: 6px 0 4px;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background: #E0F7FA;\"\u003e\n\u003cth style=\"border: 1px solid #B2EBF2; padding: 7px 10px; text-align: left;\"\u003eSize\u003c\/th\u003e\n\u003cth style=\"border: 1px solid #B2EBF2; padding: 7px 10px; text-align: left;\"\u003eBest for\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003e300 g\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003enano and single reef tanks\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003e600 g\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003ea single reef tank, regular dosing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003e1.2 kg\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003elarger reefs and fish rooms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3 style=\"margin: 16px 0 4px; font-size: 1.05em; font-weight: 600; line-height: 1.25; border-left: 4px solid #006064; padding-left: 8px;\"\u003eSpecifications\u003c\/h3\u003e\n\u003ctable style=\"border-collapse: collapse; width: 100%; font-size: 0.95em; margin: 6px 0 4px;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px; width: 38%;\"\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003eSeachem\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003eType\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003eReef magnesium supplement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003eComposition\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003eConcentrated magnesium, chloride, and sulfate salts\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003eAmmonia-free\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003eYes, unlike many liquid magnesium supplements\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003eRaises\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003eAbout 5 mg\/L magnesium per 5 g dose in 80 L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003eForm\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003ePowder (measuring scoop included)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003eWater type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003eReef and saltwater only\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003eDose\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e5 g (1 tsp) per 80 L (about 20 gal) twice weekly, dissolved first\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e\u003cstrong\u003eSizes\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #B2EBF2; padding: 7px 10px;\"\u003e300 g, 600 g, 1.2 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3 style=\"margin: 16px 0 4px; font-size: 1.05em; font-weight: 600; line-height: 1.25; border-left: 4px solid #006064; padding-left: 8px;\"\u003eRecommended Pairings\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/squeakysaquatics.com\/products\/seachem-reef-advantage-calcium-supplement\"\u003eSeachem Reef Advantage Calcium\u003c\/a\u003e to maintain calcium alongside your magnesium.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/squeakysaquatics.com\/products\/seachem-reef-buffer-ph-alkalinity-83\"\u003eSeachem Reef Buffer\u003c\/a\u003e to hold alkalinity, the third leg of reef chemistry.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/squeakysaquatics.com\/collections\/water-testing\"\u003eMagnesium and alkalinity test kits\u003c\/a\u003e so you can dose to your numbers.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/squeakysaquatics.com\/collections\/additives-supplements\"\u003eMore reef additives and supplements\u003c\/a\u003e as your system matures.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin: 16px 0 4px; font-size: 1.05em; font-weight: 600; line-height: 1.25; border-left: 4px solid #006064; padding-left: 8px;\"\u003eFAQ\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhy does magnesium matter in a reef tank?\u003c\/strong\u003e\u003cbr\u003eMagnesium keeps calcium and carbonate alkalinity from precipitating out of solution. Without enough of it, you cannot hold both calcium and alkalinity, and pH can drop.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat magnesium level should I target?\u003c\/strong\u003e\u003cbr\u003eAim for the natural seawater range, roughly 1250 to 1350 ppm, and test regularly to dose to that target.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I mix it with my alkalinity supplement?\u003c\/strong\u003e\u003cbr\u003eNo. Dose magnesium and carbonate supplements on alternate days or at least 30 minutes apart so they do not react.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow is this better than a liquid magnesium supplement?\u003c\/strong\u003e\u003cbr\u003eIt contains no ammonia, which is a common contaminant in liquid magnesium products, and it is concentrated for efficient dosing.\u003c\/p\u003e","brand":"Seachem","offers":[{"title":"300 g","offer_id":48755768197339,"sku":"636","price":6.36,"currency_code":"USD","in_stock":true},{"title":"600 g","offer_id":48755768230107,"sku":"633","price":10.33,"currency_code":"USD","in_stock":true},{"title":"1.2 kg","offer_id":48755768262875,"sku":"637","price":14.18,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0767\/5209\/3403\/files\/0636-Reef-Adv-Magnesium-300-g.png?v=1778225824","url":"https:\/\/squeakysaquatics.com\/products\/seachem-reef-advantage-magnesium","provider":"Squeaky's Aquatics","version":"1.0","type":"link"}