Grenade Black - Advanced Flowering Additive

Grenade Black is a concentrated organo-mineral flowering additive developed to support flower development, improve crop density and help plants achieve their natural genetic potential. Manufactured in the UK, this advanced PK bloom booster combines mineral nutrients with amino acids, phytohormones and other biological inputs to complement existing feeding programmes during the flowering stage.

Formulated as an alternative to synthetic chemical hardeners, Grenade Black focuses on supporting natural plant development rather than chemically altering crop growth. Its balanced combination of nitrogen, phosphorus and potassium, with a guaranteed NPK analysis of 3-9-18, provides additional flowering-stage nutrition when plants are developing and maturing their flowers.

The formula is designed to support plant energy processes, including ATP production, and encourage secondary metabolite development. Grenade Black is marketed to growers seeking denser flowers, improved harvest quality and enhanced flowering performance while maintaining their existing nutrient programme.

With a low application rate of just 0.2–0.4ml per litre, Grenade Black offers economical supplementation during weeks 3–7 of flowering. It is designed for compatibility with all nutrient regimes, making it a versatile addition to feeding programmes for indoor cultivation, greenhouse growing and professional horticulture.

Key Features

• Advanced organo-mineral flowering additive developed to support flower development and harvest density.
• Formulated as an alternative to synthetic chemical flower hardeners, with an emphasis on supporting natural crop development.
• Guaranteed NPK analysis of 3-9-18, supplying nitrogen, phosphorus and potassium.
• Combines mineral nutrients, amino acids, phytohormones and biological inputs in a concentrated liquid formulation.
• Designed to encourage denser flower development and support healthy yields.
• Formulated to support plant energy processes associated with ATP production.
• Designed to enhance secondary metabolite production during flowering.
• Supports the natural expression of a plant's genetic potential without relying on conventional chemical hardening additives.
• Recommended for use during weeks 3–7 of the flowering cycle.
• Adjustable application rate of 0.2–0.4ml per litre of nutrient solution.
• Manufacturer recommends increasing to 0.4ml per litre during flowering weeks 6 and 7 to support flower density.
• Compatible with all nutrient regimes, according to the manufacturer.
• Suitable as a supplementary bloom booster alongside existing base fertilisers.
• Highly concentrated formula offering excellent coverage from a small amount of product.
• 100ml treats up to 500 litres of nutrient solution at the minimum dosage.
• 250ml treats up to 1,250 litres at the minimum dosage.
• 1L treats up to 5,000 litres at the minimum dosage.
• 5L treats up to 25,000 litres at the minimum dosage.
• Available in 100ml, 250ml, 1L and 5L sizes.
• Made in the UK for growers seeking concentrated flowering-stage nutrition.

Specifications

Who It’s For

Grenade Black is designed for growers seeking a concentrated flowering booster to support denser flower development and improve overall harvest performance. It is particularly suited to cultivators who want to supplement their regular feeding programme with additional phosphorus, potassium and biological inputs during the middle and later stages of flowering.

Growers using established nutrient programmes can incorporate Grenade Black as a supplementary PK flowering additive, following the manufacturer's recommended dosage. Its concentrated formula is useful for both smaller growing setups and larger professional horticultural operations where economical nutrient dosing is important.

Grenade Black is also suitable for growers looking for an organo-mineral alternative to conventional chemical flower hardeners, with a formulation designed to support the natural development of their crops.

How To Use

Application Timing: Use Grenade Black during weeks 3–7 of the flowering cycle, alongside your existing nutrient feeding programme.

Dosage: Add 0.2–0.4ml per litre of water or nutrient solution, following the manufacturer's recommended application range.

Flowering Weeks 6–7: The manufacturer recommends using the upper application rate of 0.4ml per litre during weeks 6 and 7 to support natural flower density.

Mixing Guide: For a 10-litre nutrient solution, use 2–4ml of Grenade Black. For a 100-litre reservoir, use 20–40ml. Measure accurately to maintain the recommended concentration.

Nutrient Programme: Grenade Black is designed to complement existing base nutrients and flowering fertilisers. Add the measured quantity to your feeding solution and mix thoroughly. Avoid mixing concentrated fertilisers directly together before dilution.

Monitoring: Check the final EC and pH of your prepared nutrient solution where appropriate for your growing system. Because Grenade Black supplies additional nitrogen, phosphorus and potassium, consider its contribution to the overall nutrient strength of your feeding programme.

After Week 7: The manufacturer's specified application period ends at flowering week 7. Follow the feeding schedule appropriate to your crop rather than extending application beyond the recommended period without further guidance.

Storage: Keep Grenade Black in a cool, dry place between 5°C and 30°C. Close the container securely after use and follow the handling instructions on the product label.

All orders are packed in plain discreet parcels with non descript labels for your personal security.

We offer the following shipping options to the mainland UK. If you live outside mainland UK please call us on +44 (0)1142 280024.

Royal Mail delivery options (mainland UK)

Royal mail tracked  £4.75 (up to 2KG only) 2-4 working days

Royal mail tracked  £3.75 (up to 2KG only) 3-5 working days

Courier  Delivery service options (mainland) Zone A Zone A+ Zone B Zone B+

Free delivery up to 25 kilos (over £99) 1-2 working days service 
Next working day  £6.75 up to 25KG 
Next working day am £9.95 over 25KG

Courier Delivery service options Zone C Zone C+ Zone D Zone D+

Next working day  £29.95 + 75P per kg over 25KG
Next working day am £35 + 75P per KG over 25KG

All packages are shipped in plain, discrete packaging. Absolutely NO information is passed to third parties.

Please note that paid for next day delivery only applies if you order before 1PM Monday to Thursday.

Our UK delivery zones: In the UK we have 4 zones. Prices and parcel delivery times vary by zone.


Tracking your consignments

Our deliveries are handled by Parcelforce or DX or Fedex depending on the weight and location.You are able to track your parcels by using your consignment number or customer reference and postcode. If using a reference number to search, please also insert the delivery postcode. You will receive an email on the day for dispatch confirming your order and tracking number, You have the option to select a delivery window or change the day of delivery by clicking the link below and manage my delivery option.


Other Services Available

Isle of Wight & isles of Scilly £5.99 extra per consignment

Timed booked delivery £15.99 extra per consignment

Long bulky items £29.99 extra per consignment (1.4m x 0.8m 0r two persons needs to carry )

We Won't Be Beaten On Price

At Hytec Horticulture we are committed to offering the best range of hydroponic products at the best possible prices. This is why we have our Price Match Promise, whereby if you find an identical product at one of our competitors for a lower price, we will match or even beat it.

In an ever-increasingly competitive marketplace, many product lines are being sold at varying prices. We want to give you the best deal so if you find any of the products we sell (or comparable products) at cheaper prices, give us a chance to get your business, save you money, and beat that price. 

Terms & Conditions

To qualify for the Price Match Promise, the product must conform to the following:

• The product in question must be identical (it should be the same brand & model and for sale with the same terms & conditions)
• The product must be held in stock by the competitor at the time you want to make the price match
• In addition to the above, we must also have the product in stock
• We must be able to verify the lower price either by the store's website, a phone call or a written quote on headed paper
• The product is not part of a promotion, sale or clearance offer
• The product must be available from a physical store that’s open to the public
• Our Price Match Promise is not available against web-only retailers, for example, eBay or Amazon, along with factory outlets, private or liquidation sales
• Typographical errors, incorrect pricing, voucher codes or additional discounts by the competitor, including their own price match offers, are excluded 

Large & Multiple Product Orders

If you want to place a large order with multiple products (for example, you're setting up a grow room from scratch and require a full setup including tent, lights, extraction, nutrients, grow media etc) then get in touch and we will aim to match, or even beat any quotes you’ve been given.