Newmarket, Ontario (Head Office)
1175 Stellar Drive, Unit #5
Newmarket, ON L3Y 7B8
- Mon10:00am–6:00pm
- Tue10:00am–6:00pm
- Wed10:00am–6:00pm
- Thu10:00am–6:00pm
- Fri10:00am–6:00pm
- Sat10:00am–4:00pm
- SunClosed
$0.00 CAD
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Grotek Blossom Blaster Pro™ is a concentrated bloom additive for early flower development, supporting flower production during the transition into bloom and helping set up improved yield potential.
Designed to make a high impact on young flower buds, this flowering supplement focuses on floral initiation and the early bloom window before or at bud break. The formula is built around a unique phosphorus nutrient complex that targets the start of flower formation, when consistent nutrient conditions matter most. If you’re looking for a bloom enhancer that supports prolific blooming without adding extra complexity to your program, Blossom Blaster Pro™ keeps the focus on early flower performance and plant development through bloom.
Its 1-4-0 NPK profile is paired with a phosphorus form emphasized for plant uptake, supporting the nutrient demand that rises as flowering sites develop. Beyond bloom formation, this bloom additive is positioned to support improved yield and harvest quality by reinforcing key metabolic activity tied to flower development. The result is a clean, purpose-built approach for growers who want a targeted early flowering nutrient supplement with a clear role in the bloom cycle.
Blossom Blaster Pro™ is made from phosphoric acid and urea, supported by micronutrient sources that provide iron, zinc, boron, and molybdenum. It also features micronutrient sequestering technology intended to help key minerals move into the plant more efficiently, supporting increased cellular activity and the overall development of the plant and its flowers. For growers who value clear inputs and performance-focused design, this combination supports flower development while maintaining a balanced, functional root-zone environment through essential nutrient support.
For system fit, Blossom Blaster Pro™ is suitable for hydroponics and soilless (peat/coco) growing systems. It’s positioned for the flowering phase, with timing that aligns to the early bloom window around bud break and into the period leading toward fruit set. This is a good fit for growers who want a highly concentrated early flower development additive that supports profuse blooms, strengthens flower production, and promotes harvest-quality goals in streamlined hydroponic or soilless setups.
Step-by-step mixing and feeding instructions for Grotek Blossom Blaster Pro - 4 Litre.
Fill your reservoir or watering container with clean, room-temperature water first. Shake the bottle of Grotek Blossom Blaster Pro - 4 Litre well before every use. Using the feeding schedule below, measure the recommended dose and add it directly to the water while stirring. Allow the solution to mix fully before adding any other fertilizers, additives, or supplements.
Always add nutrients to water — not the other way around. Mix thoroughly between products to ensure an even, stable nutrient solution.
Vegetative stage — Blossom Blaster Pro
Flowering stage — Blossom Blaster Pro
Warning – Important Safety Information
This product may cause mild skin irritation and eye irritation. Avoid unnecessary contact with skin, eyes, and clothing. Use only as directed.
General safety precautions
Read and follow all instructions on the product label and any accompanying documentation before use. Keep out of reach of children and pets. Do not ingest. Avoid breathing vapours, mist, or dust that may be generated during handling or use.
Wear appropriate personal protective equipment (PPE), such as protective gloves, long sleeves, long pants and closed-toe footwear. When there is a risk of splashing or airborne particles, use safety glasses or other suitable eye and face protection.
First aid – skin contact
IF ON SKIN OR HAIR: Remove contaminated clothing immediately. Rinse skin with clean water for several minutes, then wash with mild soap and water. If irritation or redness develops and persists, seek medical attention. Wash contaminated clothing before reuse.
First aid – eye contact
IF IN EYES: Rinse cautiously with clean water for several minutes, keeping eyelids open. Remove contact lenses if present and easy to do. Continue rinsing. If irritation persists, obtain medical advice.
First aid – ingestion and inhalation
IF SWALLOWED: Rinse mouth thoroughly with water. Do not induce vomiting unless instructed by a medical professional. Seek medical attention if you feel unwell.
IF INHALED: Move the person to fresh air and keep them comfortable for breathing. If coughing, breathing difficulty, dizziness or other symptoms occur, seek medical assistance.
Storage and handling
Store this product in its original closed container, in a cool, dry and well-ventilated area. Protect from extreme temperatures and direct sunlight. Keep container tightly sealed when not in use.
Avoid release to drains, natural waterways or outdoor soil. Dispose of unused product and empty containers in accordance with local regulations and the directions on the label.
Important: If medical advice is needed, keep the product label or container available. Always follow the specific instructions and safety recommendations provided by the manufacturer. This safety notice is intended as general guidance and does not replace official label directions or documentation.
| Total Nitrogen (N) | 1.0% |
|---|---|
| Available Phosphoric Acid (P2O5) | 4.0% |
| Boron (B) | 0.02% |
| Molybdenum (Mo) | 0.01% |
| Zinc (Zn) | 0.2% |
| Total Iron (Fe) | 0.25% |
Available phosphoric acid provides a fast-absorbing form of phosphorus that fuels root growth, energy transfer, and strong flowering. It becomes part of the plant’s total available phosphate supply, but the two terms are not the same—available phosphoric acid is one source of phosphorus, while available phosphate refers to the entire pool of plant-available phosphorus overall.
Boric acid supplies boron, which plants need in extremely small amounts to build healthy new growth and support flowering and fruit development, but the safe range is very narrow. It’s unique because deficiency shows up first in the newest tissues while excess often burns older leaf edges, so accurate diagnosis and tiny, careful corrections matter more than with most nutrients.
Boron is essential because it stabilizes cell walls, supports root and shoot growth, and regulates sugar movement throughout the plant. What makes boron unique is its limited mobility and extremely narrow range between deficiency and excess, which causes new growth to show symptoms rapidly when levels fall out of balance.
Ferrous sulfate supplies iron in a fast-acting, reactive form that helps plants make chlorophyll properly, so new leaves can return to a deeper green when the yellowing is truly iron-related. It’s unique because it can work quickly but is highly dependent on root-zone pH and water chemistry, meaning it may only be a lasting fix when iron can stay soluble and available.
Molybdenum is important because it helps plants convert nitrogen into usable building blocks for chlorophyll and growth, and it’s unique from many nutrients because it mainly supports enzyme-driven “nutrient use” rather than directly building plant tissue.
Total iron (Fe) matters because iron supports chlorophyll development and plant energy systems, keeping new growth green and vigorous; it’s unique from many other nutrients because iron deficiency usually shows up first in young leaves even when older leaves stay green, since iron doesn’t easily move within the plant.
Total Nitrogen is important because it directly drives leafy growth, chlorophyll production, and overall growth speed, which sets the pace for the entire plant. It’s unique because the “total” number can include different nitrogen forms that behave differently in the root zone, meaning the same total amount can produce very different results depending on the nitrogen type and plant stage.
Zinc is important because it powers key enzymes and helps regulate growth hormones, which directly controls healthy new leaves, normal internode spacing, and strong growth tips; it’s unique compared to many other micronutrients because zinc problems often show up as distorted, undersized new growth and stunting, not just simple leaf yellowing.
Yes, it can if it pushes phosphorus too high or drives pH too low, because both conditions can reduce the plant’s ability to take up key micronutrients and calcium even when they’re present in the feed, which makes phosphoric acid uniquely powerful compared with slower, gentler phosphorus sources.
Sodium molybdate supplies molybdenum, a trace micronutrient that helps plants convert nitrate nitrogen into usable building material, so growth and green color stay steady; it’s unique because it works as a tiny-dose “nitrogen unlocker” rather than a bulk nutrient.
Urea can burn plants because it must convert in the root zone, and that conversion can create a concentrated, temporarily harsh micro-zone that stresses roots, especially if urea is piled, left on the surface, or not watered in. That conversion step is what makes urea unique compared with nitrogen forms that are already plant-available, so correct placement and moisture are critical.
Zinc oxide is important because it can provide zinc over time, but it is unique because it dissolves slowly, so plants can’t access much zinc from it unless the root zone conditions make it available.

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