Peters Excel CalMag Grower has a balanced N:K ratio that is engineered to trigger a healthy growth. It is a single-tank mix formula that contains all the necessary nutrients your crops will require. CalMag Grower is also compatible with calcium nitrate. Due to haz-mat restrictions on oxidizers, we are unable to ship this product via ground. We can ship up to 39 bags via motor freight delivery. This vendor allows for direct shipping of pallet quantities - 80 bags - or more ONLY. Direct shipping requires the use of the vendor's freight carrier.