General Hydroponics 2.2# KoolBloom (12/CS)

General Hydroponics KoolBloom 2-45-28 is a powdered bloom-booster supplement designed for use at the final stage of a plant’s life cycle. Its highly concentrated 2-45-28 NPK formula delivers a focused dose of phosphorus and potassium to support heavier fruits and flowers and to speed the ripening process in annual flowers and herbs.

KoolBloom 2.2 lb Specifications

Physical and formula specifications for General Hydroponics KoolBloom 2-45-28, 2.2 lb powder (SKU HGC732531).

Why Choose General Hydroponics KoolBloom

KoolBloom is a targeted end-of-cycle supplement, not a base nutrient. It is built around a 2-45-28 NPK ratio, which means nitrogen is intentionally kept low while phosphorus and potassium are concentrated at levels specifically intended to drive flower development and trigger ripening rather than maintain vegetative growth.

• Highly concentrated formula: The powder form delivers a high-strength dose of phosphorus and potassium without adding significant water weight, making it practical for growers managing reservoir volume in a recirculating system.
• Targeted for annual flowers and herbs: The formulation is described by the manufacturer as designed for plants that complete their life cycle in a single season, including fruiting crops grown under controlled conditions.
• Ripening-element support: Beyond the P and K headline numbers, KoolBloom includes what General Hydroponics describes as precise amounts of ripening elements — trace components intended to support the finishing stage of the bloom cycle.
• Late-cycle only: Using a high-phosphorus, moderate-nitrogen supplement only at the end of the cycle avoids pushing unwanted vegetative growth while giving the plant the mineral input it needs to bulk up flowers and fruit.
• Case-format availability: The 12-per-case format (12/CS) is suited to commercial operations or multi-facility growers who run the same end-of-cycle feeding program across multiple rooms.

Best Uses for KoolBloom 2-45-28

KoolBloom is a single-stage supplement. The canonical description states it is to be used only at the very end of a plant’s life cycle. This specificity matters: it is not a general-purpose bloom fertilizer and should not be used from early flower through harvest.

• Final weeks of the bloom cycle: Applied during the last two to four weeks before harvest, when plants benefit from a drawdown of nitrogen and an increase in phosphorus and potassium to support fruit and flower bulk.
• Annual flowering crops: Annuals — plants that complete seed-to-harvest in one season — are the stated target crop type. This covers the broad range of fruiting and flowering crops common in controlled-environment agriculture.
• Herb finishing: Fast-cycling herbs that produce essential oils or flower-derived compounds can be supported through the final ripening stage with a high-P/K supplement like KoolBloom.
• Hydroponic and soilless systems: As a General Hydroponics product, KoolBloom is formulated to dissolve cleanly in water and is compatible with the nutrient solution management approach used in recirculating DWC, NFT, and drain-to-waste systems.
• Commercial multi-batch operations: The 12/CS case format is a practical choice for facilities running continuous-harvest cycles where a consistent late-stage supplement is part of a documented feed schedule.

If you are building out a late-stage feeding program, pairing KoolBloom with a beneficial microbe inoculant such as Advanced Nutrients Tarantula or a root-health additive like Earth Juice Hi-Brix Molasses can support overall plant resilience during the final flush period.

Dosing Guidelines

The canonical product description specifies that KoolBloom is to be used only at the very end of a plant’s life cycle. It is a late-stage supplement, not a continuous-feed nutrient. Using it earlier in the bloom phase or into vegetative growth would introduce a nitrogen-low, phosphorus-heavy profile at a stage when balanced nutrition is required, which is not the intended application.

General handling guidance for powdered bloom supplements of this type:

1. Measure the recommended dose per gallon or litre using a calibrated scale or measuring scoop — powders can pack unevenly, so weight-based measurement is more precise than volume.
2. Pre-dissolve the powder in a small amount of warm water before adding to the main reservoir or spray tank. This helps prevent undissolved particles from settling.
3. Add to your reservoir after adjusting the base pH of the water to the target range for your system (typically 5.5–6.2 for hydroponic recirculating systems).
4. Mix thoroughly and check EC against the target value for the late-bloom stage. KoolBloom’s high phosphorus content will raise EC, so back-calculate the full nutrient solution EC before finalizing the mix.
5. Follow the manufacturer’s published feed schedule for exact dose rates and timing. General Hydroponics publishes feeding charts on their website for their full product line.

Because KoolBloom is a concentrated supplement rather than a complete nutrient, it is intended to be used alongside, not in place of, the base nutrient program.

Sources & Further Reading