Water-soluble hydroponic fertilizer formulated specifically for tomato and fruiting vegetable production. MasterBlend 4-18-38 Tomato Formula is part of a 2 or 3-part nutrient system that provides complete balanced nutrition for tomatoes, peppers, cucumbers, and other fruiting crops in hydroponic, aquaponic, and fertigation systems. When combined with calcium nitrate and magnesium sulfate, it delivers the complete nutrient profile needed for vigorous vegetative growth, heavy fruit set, and high-quality yields.
Tomato-Specific Nutrient Formulation
The 4-18-38 NPK ratio delivers high phosphorus and potassium levels optimized for fruiting vegetable production. Elevated phosphorus supports strong root development, flowering, and fruit set, while high potassium enhances fruit quality, flavor, firmness, and shelf life. The moderate nitrogen level promotes balanced vegetative growth without excessive foliage that can reduce fruit production.
Key Features
- NPK analysis: 4-18-38 (nitrogen-phosphorus-potassium)
- Formulated specifically for tomatoes and fruiting vegetables
- Part of a 2 or 3-part complete nutrient system
- 100% water-soluble for complete dissolution
- High purity formulation prevents clogging
- Compatible with hydroponic, aquaponic, and fertigation systems
- Includes essential micronutrients
- Suitable for all continuous liquid feed programs
- Professional-grade commercial formulation
Application - 2 or 3-Part Nutrient System
This product must be used with calcium nitrate and magnesium sulfate to create a complete plant nutrient solution. MasterBlend 4-18-38 Tomato Formula alone does not provide all essential nutrients.
2-Part System: Combine MasterBlend 4-18-38 with calcium nitrate for a complete nutrient solution.
3-Part System (Recommended): Combine MasterBlend 4-18-38 with calcium nitrate and magnesium sulfate (Epsom salt) for optimal nutrition.
Typical mixing ratio: For each gallon of nutrient solution, dissolve separately then combine:
- MasterBlend 4-18-38: 2-3 grams
- Calcium Nitrate (15-5-0 or 15.5-0-0): 2-3 grams
- Magnesium Sulfate: 1-1.5 grams
Adjust concentrations based on crop stage, variety, and environmental conditions. Monitor EC and pH regularly. Important: Always dissolve each component separately in water before combining to prevent nutrient lockout.
Ideal For
Tomatoes (all varieties), peppers, cucumbers, eggplant, squash, melons, and other fruiting vegetables. Suitable for commercial greenhouse production, vertical farms, aquaponic systems, and home hydroponic gardens. Works in all hydroponic system types including NFT (nutrient film technique), DWC (deep water culture), ebb and flow, drip irrigation, and Dutch bucket systems.
Specifications
- NPK ratio: 4-18-38
- Form: Water-soluble powder
- Solubility: 100% (no residue)
- Purity: High-grade formulation
- Package size: 25 lb bag
- Weight: 26 lb (including packaging)
- SKU: MB-TOMATO-25lb.
Complete Nutrient System Requirements
Required components for complete nutrition:
- MasterBlend 4-18-38 Tomato Formula (this product)
- Calcium Nitrate 15-5-0 or 15.5-0-0 (sold separately)
- Magnesium Sulfate / Epsom Salt (sold separately)
Store in cool, dry location away from moisture. Keep components separate until ready to mix.
- Easy to use: Use this fertilizer in conjunction with Yara calcium nitrate (15% N, 19%Ca) and Giles magnesium sulfate(9.8%Mg, 12.9%S) to formulate a complete fertilizer solution.
- High Analysis: Guaranteed Analysis: 4-18-38 complete with chelated micronutrients.
- Pure: Low in sodium, chloride and heavy metals.
- Water Soluble: Completely soluble in water. Ideal for making concentrated stock solutions for automatic fertilizer injection systems.
Guaranteed Analysis:
| Total Nitrogen (N) | 4% |
| 4% Nitrate Nitrogen | |
| Available Phosphate (P2O5) | 18% |
| Soluble Potash (K2O) | 38% |
| Magnesium (Mg) (Total) | 0.30% |
| 0.30% Water Soluble Magnesium (Mg) | |
| Boron (B) | 0.20% |
| Copper (Cu) | 0.05% |
| 0.05% Chelated Copper (Cu) | |
| Iron (Fe) | 0.40% |
| 0.40% Chelated Iron (Fe) | |
| Manganese (Mn) | 0.20% |
| 0.20% Chelated Manganese (Mn) | |
| Molybdenum (Mo) | 0.01% |
| Zinc (Zn) | 0.05% |
| 0.05% Chelated Zinc (Zn) | |
Plant nutrients derived from:
potassium nitrate, potassium phosphate, potassium sulfate, magnesium sulfate, boric acid, copper EDTA, copper sulfate, iron DTPA, manganese EDTA, sodium molybdate, zinc EDTA
Potential Basicity:
220 Lbs. calcium carbonate equivalent per ton.
Maximum Solubility:
1.8 Lbs. per gallon
CAUTION: Some crops may be injured by application of Boron.
This fertilizer is to be used only on soils that respond to Molybdenum. Crops high in Molybdenum are toxic to ruminant animals.
Mixing rates:
Established plants: Mix 8 oz. of Master Blend 4-18-38 in 100 gallons of water, along with 8 oz. of calcium nitrate and 5 oz. of magnesium sulfate. For small volumes use 2.25 grams Mater Blend 4-18-38, 2.25 grams calcium nitrate and 1.5 grams magnesium sulfate per gallon of final volume working solution. This will give a nutrient profile of approximately:
116ppm N - 47ppm P - 188ppm K - 41ppm Mg - 113ppm Ca - 58ppm S
2.4ppm Fe - 0.3ppm Zn - 1.2ppm B - 0.3ppm Cu - 0.06ppm Mo - 1.2ppm Mn - 12ppm Cl
Transplants: Mix 8 oz. of Master Blend 4-18-38 in 100 gallons water, along with 6 oz. of calcium nitrate and 4 oz. of magnesium sulfate.
MasterBlend 4-18-38 Tomato Formula Hydroponic Fertilizer - 25 lb
MasterBlend 4-18-38 Tomato Formula Hydroponic Fertilizer - 25 lb
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