Intense Mag-Cal is as its name suggests a Magnesium and Calcium additive for addressing deficiencies and also as a conditioner for R.O. water.
Many customers using coco and soil use this product as a matter of course up until a few weeks into flower to avoid deficiencies in magnesium and calcium which have become fairly common in recent years. Care should be taken to avoid over-use later on in the flowering cycle as Mag-Cal also includes a fair amount of Nitrogen which is not conducive to abundant fruiting/flowering. If a magnesium or calcium deficiency is experienced later on in the cycle then look to the Canna Mono Elements to remedy this but as always extra care should be taken with identifying and treating deficiencies - as it is all too easy to produce toxicity or throw out the whole balance of your nutrient regime.
Intense Mag-Cal is available in 1l, 5l, and 10l bottles.