VA & VB bottles have been engineered to provide extremely fast growth with short internodes and gives you that added boost to help build up overall health of your plants for fast forming flowers during the flowering stage. We use two forms of nitrogen in a balanced ratio that causes extremely fast growth. By allowing you the grower to customize your delivery of these bottles, you can acheive better yeilds. use VA & VB with MB to create the perfect balance of mineral elements for extremely fast growing plants.