Reef Advantage Magnesium， 4 kg / 8.8 lbs</br></br><div style="text-align:left"><b>[Product Information]</b><br><ul><li>Raises Magnesium And Contains No Ammonia</li><li>A Concentrated Optimized Blend Of Magnesium， Chloride， And Sulfate Salts Designed To Restore Depleted Levels Of Magnesium</li><li>Minimal impact to the ionic ratios found in natural sea water</li><li>Contains No Ammonia， A Common Contaminant In Every Liquid Magnesium Supplement On The Market</li><li>300 Grams Treats 1200 Us Gallons</li></ul></div></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br><img src='http://ecx.images-amazon.com/images/I/41tq1VeTbrL.jpg' noproxy></br>