Products

Green House Feeding CalMag is a high-quality water-soluble mineral fertiliser designed to prevent and correct calcium and magnesium deficiencies in all plant types. The formula contains nitrogen, calcium and magnesium in an easily absorbed form and is ideal for use with soft water, reverse-osmosis (RO) water, rainwater, as well as in hydroponic, coco and soil growing. Thanks to its high purity, the product contains no chlorine, sodium or heavy metals.

Green House Feeding CalMag is a professional mineral supplement developed to provide optimal amounts of calcium and magnesium – two vital elements for proper plant development. Calcium contributes to the formation of strong cell walls and stimulates the development of roots and new tissue, while magnesium is a key component of chlorophyll and plays a vital role in photosynthesis.

The product is particularly suitable when using reverse-osmosis (RO) water, rainwater or very soft water, where the natural calcium and magnesium content is insufficient. Adding CalMag restores the mineral balance and prevents typical symptoms such as interveinal chlorosis, necrotic spots, deformed leaves and stunted growth.

Thanks to its 100% water-soluble formula, nutrients become immediately available to plants. CalMag can be used through fertigation, hydroponic systems or foliar application, and is compatible with all main Green House Feeding mineral fertilisers – Hybrids, Short Flowering, Long Flowering and Booster – as well as nutrient programmes from other manufacturers.

Composition (EC fertiliser):

✔️ Total nitrogen (N): 13.5%

• Nitrate nitrogen (NO₃): 13.1%
• Ammoniacal nitrogen (NH₄): 0.4%

✔️ Calcium oxide (CaO): 16.7% (water-soluble)

✔️ Magnesium oxide (MgO): 6.0% (water-soluble)

✔️ EC at 1 g/L: 1.2 mS/cm

✔️ Does not contain:

• Chlorine
• Sodium
• Heavy metals

Benefits

✔️ Prevents and corrects calcium and magnesium deficiency

✔️ Suitable for reverse-osmosis (RO) water and rainwater

✔️ Improves cell-wall strength

✔️ Stimulates the development of a strong root system

✔️ Improves photosynthesis and chlorophyll formation

✔️ Supports the formation of healthy flowers and quality fruit

✔️ Ensures rapid absorption thanks to high solubility

✔️ Compatible with most mineral nutrition programmes

✔️ Can be used alone or with fertilisers from other manufacturers

✔️ Contains no chlorine, sodium or heavy metals

Application

Suitable for:

• Vegetable crops

• Fruit trees

• Flowers

• Ornamental plants

• Hydroponic systems

• Coco substrates

• Soil growing

• Fertigation

• Foliar feeding

• Professional and hobby growing

📋 Instructions for use

Base dosage

✔️ 0.1 – 0.5 g per 1 litre of water

For soft water (RO / rainwater)

✔️ 0.5 g/L water (about 0.6 EC)

For hard water or rich soil

✔️ 0.2 g/L, 1–2 times per week (as needed)

Foliar application

✔️ 0.2 g/L, every 10 days, only in the event of confirmed calcium or magnesium deficiency.

For automatic dosing systems

✔️ Preparation of concentrate: 10–15 kg product per 100 litres of water for systems such as Dosatron, Netafim and others.

⚠️ Important

• Do not mix Green House Feeding CalMag with other calcium supplements.
• When using the Green House Feeding programme, you can stop using CalMag around the 6th week of flowering and switch to GHF Calcium Chelate if you wish to continue supplying calcium without additional nitrogen.

💡 Tip from Urban Botaniks: If you use a reverse-osmosis (RO) system, Green House Feeding CalMag should be the first addition to the water before the other fertilisers. This will restore the required calcium and magnesium content and provide an optimal environment for the absorption of all other nutrients. 🌱

GH Powder Feeding Bio Bloom is an organic powdered fertiliser for the flowering stage, suitable for all plant types. It contains all the necessary trace elements for an excellent yield. Its natural ingredients encourage beneficial soil microorganism development.
Use together with GH Powder Feeding Bio Grow and GH Powder Feeding BioEnhancer.

• Certified for organic production
• Completely natural and pure ingredients
• Ideal for outdoor use
• Easy to use
• High natural phosphorus content
• Slow release in soil over 8 weeks
• N-P-K: 4-9-9

Directions for use:

Applied to soil only by mixing with the substrate.

• When transplanting, mix thoroughly with the substrate.
• At a later stage, sprinkle over the soil surface.

Application rates:
Adjusted to the flowering duration of different types.

Recommendations and advice:

• The properties of this fertilizer may change when exposed to sunlight and high humidity
• For best results, do not store unpacked fertiliser for more than 3 years.
• The product must not enter the sewer system.
• The soil surface may develop beneficial soil micromycete (fungal) mycelium, which improves its structure and increases nutrient uptake. Do not remove it.

Contents: hydrogen(C), nitrogen(N), phosphorus(P), potassium(K), magnesium(Mg), sulphur(S) in natural form and 31% organic matter

GH Powder Feeding Bio Enhancer is an organic biostimulant suitable for use with all types of plants. It contains seaweed extract, humic acids and strains of beneficial microorganisms Trichoderma harizanum and Bacillus subtilis. Seaweed is a natural source of many minerals and organic acids that have a beneficial effect on plant development, while the microorganisms enrich the soil and improve micronutrient uptake.
Use together with GH Powder Feeding Bio Grow and GH Powder Feeding Bio Bloom.

• Certified for organic production
• Completely natural and pure ingredients
• Ideal for outdoor use
• Easy to use
• Contains 75% humic acids
• N-P-K: 1-0-8
• Includes a measuring scoop

GH Powder Feeding Bio Enhancer includes a rich range of organic ingredients, each with its own specific effect on soil and plants.

Humic acids occur naturally in soil and are part of humus, the main organic component of soil. The humic acids in this soil improver are obtained from natural deposits of Leonardite, widely known as a soil improver and biostimulant. They improve the chelation of micronutrients, i.e. their conversion into a form available to plants. They are particularly important for iron (Fe) uptake, which improves photosynthesis, sugar production and therefore plant flavour.

Seaweed extract contains 62 trace elements, amino acids and phytohormones. It increases plants' stress resistance and nutrient uptake from the substrate, as well as seed germination.

Trichoderma harizanum is a micromycete that stimulates root-system development and protects it from fungal diseases.

Bacillus amyloliquefacienc (subtilis) is a bacterium naturally found in soil and used for the biocontrol of soil and leaf pathogens. It destroys fungal hyphae, and in the soil it converts nitrogen (N) and phosphorus (P) into forms available to plants.

Application method:
Mix with water and water plants once every 2 weeks throughout the growing period. It can also be used as a foliar spray.

The product raises the pH to 8.5 when mixed with water. 

Adjust the pH to 5.0 when growing in coco substrate! No pH adjustment is needed for soil growing and foliar feeding.

Application rates: 

• Watering – 0.5-1 g/l every 2 weeks 
• Foliar spray –  3-5 g per 10 litres of water once every 2 weeks during vegetation
• For cuttings – soak the substrate with 0.25-1 g/l of water before placing the cutting
• For seed germination – soak the seeds for 8-12 hours in a solution of 0.5-1 g/l of water 
• For mother plants – use as a foliar spray 24 hours before taking cuttings

The prepared solution remains usable for up to 24 hours after preparation!

Recommendations and advice:

• The properties of this fertilizer may change when exposed to sunlight and high humidity
• For best results, the unpacked fertilizer should not be stored for more than 2 years
• Beneficial soil micromycete (fungal) mycelium may appear on the soil surface; it improves soil structure and increases nutrient uptake. Do not remove it!

Contents: 75% humic acids, 10⁶ cfu/g Trichoderma harizanum, 10⁷ cfu/gBacillus amyloliquefacienc (subtilis), Ascophyllum nodosum seaweed extract (Alginic acid, Mannitol, Fucoidans, Amino Acids)

🔹 Powder Feeding BioGrow is an organic powdered fertilizer intended for the vegetative stage of fast-growing plants. With its balanced NPK ratio of 7-2-4, this fertilizer provides all the essential nutrients necessary for healthy growth. It is enriched with active mycelium, which stimulates microorganisms in the soil and improves nutrient uptake. Suitable for use in soil, coco fiber, and similar substrates. 

🔹 Detailed specifications:

• Manufacturer: Green House Feeding
• Model: Powder Feeding BioGrow
• Form: Powdered mix
• NPK ratio: 7-2-4
• Composition: Organic minerals, active mycelium
• Application: Vegetative plant growth
• Compatibility: Soil, coco fiber, and similar substrates
• Duration of action: Up to 8 weeks with a single application
• Country of production: The Netherlands

🔹 Recommendations and directions for use:

1. Mix the contents thoroughly before use.
2. For vegetative growth: Use 3 g of fertilizer per liter of substrate.
3. For mother plants: Use 2–3 g per liter of substrate every two months.
4. Incorporate the fertilizer directly into the substrate before planting or apply it as a top dressing.
5. Water the plants regularly to activate the release of nutrients.

✅ Benefits of use:

• Easy to use: The powdered form ensures easy dosing and application.
• Long-lasting action: A single application provides nutrition for up to 8 weeks.
• Improved nutrient uptake: The active mycelium stimulates microorganisms in the soil, improving nutrient uptake.
• Suitable for various substrates: It can be used in soil, coco fiber, and similar substrates. 

Green House Powder Feeding Booster is a mineral powdered fertiliser for boosting flowering and fruiting(booster). Its formula also includes micronutrients to balance the nutrient solution and ensure high uptake of vital phosphorus (P), potassium (K) and magnesium (Mg). With this flowering booster you can reach the full potential of your plants.

Combine with GH Powder Feeding short flowering or GH Powder Feeding long flowering or GH Power Feeding Hybrids.

• Easy to use, store and transport
• Longer shelf life than liquid fertilisers
• The prepared solution remains usable for up to 1 week
• N-P-K: 0-30-27
• Includes a measuring scoop

Green House Powder Feeding Booster is a balanced supplement to the base flowering fertiliser. Liebig's law (Liebig barrel) is observed – plant development is determined not by nutrients that are abundant, but by those required in small doses. For this reason, in addition to the main phosphorus and potassium, micronutrients have also been added, without which the main elements cannot be fully absorbed. This makes this growth booster exceptionally effective.

Directions for use:

Apply during flowering together with a base flowering fertiliser GH Powder Feeding short flowering or GH Powder Feeding long flowering or GH Power Feeding Hybrids

• Soil application – dissolve the recommended dose in the irrigation water. Stir vigorously for 2-3 minutes. Apply the fertiliser with every second watering.
• Hydroponics / Coco – dissolve the recommended dose in the irrigation water. Stir vigorously for 2-3 minutes. Use the nutrient solution with every watering.

Application rates: 

Recommendations and advice:

• Stop using the fertiliser 10 days before harvesting.
• Fertiliser doses are calculated for dissolving in water with EC=0.0
• The resulting solution can be stored for up to 7 days at room temperature in the dark (it maintains stable pH and EC values)
• The colour of the solution may change when exposed to sunlight
• Recommended solution pH during flowering: 5,8-6,5

In addition to the main NPK components, it also contains: magnesium (Mg), boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn)

Application schedules:

• Soil
• Coco
• Rockwool 
• Simplified (Keep it simple!)

GH Powder Feeding Calcium is a highly concentrated calcium supplement, specially created to support healthy plant growth. Calcium is an important micronutrient that plays a key role in cell-wall development and supports the transport of other nutrients within the plant.

GH Powder Feeding Calcium can be used in both hydroponic systems and traditional soil media. Easy to mix and apply, this product provides the required calcium dose to prevent deficiency symptoms and support normal cell processes. The product is suitable for all growth stages, integrating seamlessly into your current feeding plan. With GH Powder Feeding Calcium, you will notice improved plant health and vitality, leading to better harvests and product quality.

Green House Powder Feeding Grow is a concentrated powdered fertiliser for the growth stage, suitable for all plant types and growing methods. Its formula contains optimal concentrations of the micronutrients most needed during growth for greener, healthier and more resilient plants.

• Easy to use, store and transport
• Longer shelf life than liquid fertilisers
• Also suitable for foliar feeding
• The prepared solution remains usable for up to 1 week
• N-P-K: 24-6-12
• Includes a measuring scoop

Application method

• Soil - dissolve the recommended dose in the irrigation water. Stir vigorously for 2-3 minutes. Apply the fertiliser with every second watering.
• Hydroponics/ Coco - dissolve the recommended dose in the irrigation water. Stir vigorously for 2-3 minutes. Use the nutrient solution with every watering.
• Foliar - dissolve 100ml of the nutrient solution in 900ml of water.

Application rates 

• Young plants: 2,5-5 g / 10 l water 
• Mother plants (3 weeks+): 10 g / 10 l water

Recommendations and advice:

• Fertiliser doses are calculated for dissolving in water with EC=0.0
• The resulting solution can be stored for up to 7 days at room temperature in the dark (it maintains stable pH and EC values)
• The colour of the solution may change when exposed to sunlight
• Recommended solution pH: 5,5-6 

In addition to the main NPK ingredients, it also contains: boron(B), copper(Cu), iron(Fe), manganese(Mn), molybdenum(Mo), zinc(Zn)

Green House Powder Feeding Long flowering is a concentrated powdered fertiliser for the growth and flowering stages, suitable for plants with a long flowering period. Its formula includes all necessary micronutrients for large flowers and healthy plants. It contains a high amount of phosphorus (P), needed to develop a strong root system. Suitable for the entire growing period.

For better results, combine with GH Powder Feeding Grow and GH Powder Feeding Booster

• Easy to use, store and transport
• Longer shelf life than liquid fertilisers
• The prepared solution remains usable for up to 1 week
• N-P-K: 18-12-18
• Includes a measuring scoop

Directions for use:

• Soil - dissolve the recommended dose in the irrigation water. Stir vigorously for 2-3 minutes. Apply the fertiliser with every second watering.
• Hydroponics / Coco – dissolve the recommended dose in the irrigation water. Stir vigorously for 2-3 minutes. Use the nutrient solution with every watering.

Application rates: 

• Young plants: 2.5-7 g / 10 L water
• Growth/flowering: 7-10 g / 10 L water

Recommendations and advice:

• Stop using the fertiliser 10 days before harvesting.
• Fertiliser doses are calculated for dissolving in water with EC=0.0
• The resulting solution can be stored for up to 7 days at room temperature in the dark (it maintains stable pH and EC values)
• The colour of the solution may change when exposed to sunlight
• Recommended solution pH: during growth 5.5-5.8; during flowering 5.8-6.8

In addition to the main NPK components, it also contains: magnesium (Mg), boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn)

Application schedules:

• Soil
• Coco
• Rockwool 
• Simplified (Keep it simple!)

Green House Powder Feeding Short Flowering is a concentrated powdered fertiliser for the growth and flowering stages, suitable for plants with a short flowering period. Its formula includes all necessary micronutrients and a higher amount of readily available potassium (K), needed to achieve an excellent yield even with a shorter flowering period. It is suitable for the entire growing cycle.

For better results, combine with GH Powder Feeding Grow and GH Powder Feeding Booster

• Easy to use, store and transport
• Longer shelf life than liquid fertilisers
• The prepared solution remains usable for up to 1 week
• N-P-K: 16-6-26
• Includes a measuring scoop

Directions for use:

• Soil - dissolve the recommended dose in irrigation water. Stir vigorously for 2-3 minutes. Apply the fertiliser with every second watering.
• Hydroponics / Coco - dissolve the recommended dose in irrigation water. Stir vigorously for 2-3 minutes. Use the nutrient solution with every watering.

Application rates:

• Young plants: 2.5-7 g / 10 L water
• Growth/flowering: 7-10 g / 10 L water

Recommendations and advice:

• Stop using the fertiliser 10 days before harvesting.
• Fertiliser doses are calculated for dissolving in water with EC=0.0
• The resulting solution can be stored for up to 7 days at room temperature in the dark (it maintains stable pH and EC values)
• The colour of the solution may change when exposed to sunlight
• Recommended solution pH: during growth 5,5-6; during flowering 6-6,5

In addition to the main NPK components, it also contains: magnesium (Mg), boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn)

Application schedules:

• Soil
• Coco
• Rockwool 
• Simplified (Keep it simple!)

Green House Powder Feeding Hybrids is a concentrated powder fertiliser for the growth and flowering stages, suitable for hybrid plants. Its formula includes all essential micronutrients. The increased magnesium (Mg) content and added sulphates help improve yields in hybrid varieties. They also support the accumulation of essential oils, terpenes and flavonoids in plants. Suitable for the entire cultivation period.

For better results, combine with GH Powder Feeding Grow and GH Powder Feeding Booster

• Especially suitable for hydroponic growing
• Easy to use, store and transport
• Longer shelf life than liquid fertilisers
• The prepared solution remains usable for up to 1 week
• N-P-K: 15-7-22
• Includes a measuring scoop

Directions for use:

• Soil - dissolve the recommended dose in the watering water. Stir vigorously for 2–3 minutes. Apply the fertiliser with every second watering.
• Hydroponics / Coco - dissolve the recommended dose in irrigation water. Stir vigorously for 2-3 minutes. Use the nutrient solution with every watering.

Application rates:

• Young plants: 2.5-7 g / 10 L water
• Growth/flowering: 7-10 g / 10 L water

Recommendations and advice:

• Stop using the fertiliser 10 days before harvesting.
• Fertiliser doses are calculated for dissolving in water with EC=0.0
• The resulting solution can be stored for up to 7 days at room temperature in the dark (it maintains stable pH and EC values)
• The colour of the solution may change when exposed to sunlight
• Recommended solution pH: during growth 5,5-6; during flowering 6-6,5

In addition to the main NPK components, it also contains: magnesium (Mg), boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn)

Application schedules:

• Soil
• Coco
• Rockwool 
• Simplified (Keep it simple!)

Complete organic fertiliser for soil, aero and hydro. Perfectly soluble, suitable for all cultivation methods and all types of drip irrigation.

For soil, adding Bioponic Mix is recommended. For hydro, always use Bioponic Mix.
For soil, it is not necessary to adjust the pH level; however, the optimal values are 5.5-6.2 before adding fertilisers.
For hydroponics, pH can reach 7.5 without problems. If it rises above this value, it should be brought back to 6 gradually over 5-6 days.
Electrical conductivity values are not indicative when using organic fertilisers; aim for EC 0.8-1.0