Epsom Salt (Magnesium sulfate)
Epsom salt helps plants absorb nutrients, it’s a crucial mineral required for photosynthesis. It can be used during watering or as a foliar spray. During the Great White Shark grow I started using Epsom Salt on day 89, however, in future grows I will start using Epsom as soon as I start using other nutrients. It can be purchased at a gardening store or at a pharmacy, make sure that it contains 100% magnesium sulfate without any other additives.