Growth Technology Optimum Bloom A+B

Optimum Bloom is the flowering-stage companion to Optimum Grow, completing the two-part base nutrient system developed by nutrient chemist Carl Barry and blended in Western Australia by Growth Technology. Where Optimum Grow is built around nitrogen-led vegetative development, Optimum Bloom shifts the nutrient profile to reflect the different demands of reproductive growth; reduced nitrogen, elevated phosphorus and potassium, and a composition calibrated to support flower development, fruit set, and final yield quality.

The combined A&B analysis reflects this shift clearly. Total nitrogen drops to 5.62% (from 6.01% in Grow), while phosphorus increases to 2.25% (from 1.00%) and potassium rises to 8.74% (from 7.51%). This NPK rebalancing supports energy transfer and flower site development via phosphorus, while potassium drives carbohydrate transport, enzyme activity, and water regulation during the high-demand flowering period. Calcium at 3.50% and magnesium at 1.00% maintain cell wall integrity and chlorophyll function through bloom, and the full trace element profile carries through from the grow phase to cover micronutrient requirements to the end of the cycle.

Add part A to water at 4 ml per litre and mix thoroughly before adding an equal volume of part B. Add any additional additives, then adjust pH to between 5.5 and 6.5 and fine-tune dilution rate to achieve your target EC. Store in a cool, dark place. Pair with Optimum Grow for the vegetative stage.