Humboldt Nutrients HNB404 16-Ounce Bloom, NPK 0-6-5 Formula Humboldt nutrients bloom npk 0-6-5 formula Developed without the use synthetic chelates Bloom contains a phosphorus booster which improves plant photosynthesis, metabolism, genetics and eventually crop quality and yield Designed to be used together, along with Micro as a complete growing nutrient system for hydroponics as well as other growing mediums Plant growth, flowering and fruiting depend on the correct balance of phosphorus and potassium