Aptus Bloomboost, 5 LiterBLOOMBOOST Bloom Booster and Quality Enhancer Aptus Bloomboost is an additive used throughout the entirety of the fruiting and flowering periods of a plant's lifespan. Bloomboost contains a blend of plant available elements including potassium, sulfur, and boron that work together to increase fruit flower size, fiber mass, and quality. Aptus has designed this product to provide these three elements in precise amounts at desired times during the plants