Dyna-Gro SUPERthrive Mag-Pro - 1 GallonDescription Product Name: SUPERthrive Mag Pro 1 gal Formula: SUPERthrive Mag Pro 2 15 4 is a unique mix, high in phosphorus, magnesium and sulfur. This supplement is designed to be used alongside any complete nutrition formula as a booster to aid in flowering and to develop large, vibrant, fragrant flowers. The nutrients in Mag Pro are immediately available to plants, helping them access what they need at critical times of flower formation, thereby