SNS Sierra Natural Science Pro Stimulators - Nutrients and Additives for Hydroponics and Horticulture use.SNS 604 A & B are a concentrated blend of plant and marine extracts to be used throughout the plants growing and flowering cycle. SNS 604A & B contain the natural building blocks of life and are used in addition to your regular fertilizer program. They enhance mineral nutrient uptake and transport in your plants and facilitate the conversion and biosynthesis of complex secondary aromatic compounds while enhancing metabolic growth, promoting root and flower development, encouraging fruit swelling, and facilitating essential oil production. 604A & B will also encourage beneficial microbial activity in the root zone. With SNS 604A & B your plants with increase in flavor, yield and color! SNS 604A and SNS 604B are concentrated, 100% organic, completely water soluble and safe for everyday use.