KORALLEN ZUCHT - ZEOMAG MAGNESIUM GRANULATE 1KG Korallen Zucht Sale! from 2174 /per Qty. Add to Cart This item is currently on backorder but you can still purchase it now and we'll ship as soon as more become available. ZEOvit ZEOmag is a pure magnesium granulate to be used in calcium reactors (5-15% of total media volume) to maintain magnesium levels. Magnesium is easily added without chloride and without disturbing the ionic balance in your tank. Granulate size 6-12 mm.