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Tomato Formula Combo


Masterblend’s Tomato COMBO Formula is an easy to use, 3-part fertilizer system for the home gardener that uses the same technical grade fertilizer trusted by professional growers for decades. The kit contains three parts to be mixed together in water resulting in the ultimate formula for amazing tomatoes, lettuce, basil, cucumber and other fruiting vegetables. The first component is our popular water-soluble 4-18-38 formula. The second is Calcium Nitrate (CAL-NIT), third is Magnesium Sulfate (MAG-SUL) or Epsom salt for full and fast absorption of nutrients by the plant. Combine these three formulas with water according to the directions and you have pure nutrition your garden vegetables will love.

SKU: masterblend-tomatoCombo Category: Tags: ,
4-18-38 Tomato Formula Guaranteed Analysis
Total Nitrogen (N)
3.5% Nitrate Nitrogen
0.5% Ammoniacal Nitrogen
Available Phosphate (P2O5) 18%
Soluble Potash (K2O) 38%
Magnesium (Mg) (Total)
0.50% Water Soluble Magnesium (Mg)
Boron (B) 0.20%
Copper (Cu)
0.05% Chelated Copper (Cu)
Iron (Fe)
0.40% Chelated Iron (Fe)
Manganese (Mn)
0.20% Chelated Manganese (Mn)
Molybdenum (Mo 0.01%
Zinc (Zn)
0.05% Chelated Zinc (Zn)
  • Plant nutrients derived from: potassium nitrate, potassium phosphate, ammonium phosphate, potassium chloride, magnesium sulfate, boric acid, copper EDTA, iron DTPA, manganese EDTA, sodium molybdate, zinc EDTA.
  • Potential Basicity:  209 lbs. Calcium Carbonate Equivalent Per Ton.


Weight 11.34 kg, 1.0 kg, 500g, 250g, 100g

Spray Tank:
Mix 8 oz. in 100 gallons of water, along with 8 oz. of Calcium Nitrate and 5 oz. of Magnesium Sulfate.
Apply 1 quart per square foot as a normal watering on a 1 to 2 week basis. Adjust PH to 6.4 – 7.7.

Mix 8 oz. in 100 gallons of water, along with 6 oz. of Calcium Nitrate and 4 oz. of Magnesium Sulfate.
Apply on a 2 – 3 week basis.

Maximum Solubility: 3.5 lbs. Per gallon.

Use this product only after a thorough water quality analysis has been performed. Discuss results with an expert. Weekly testing may be necessary. Be certain to monitor media quality as well. Soil and plant tissue analysis are also recommended.

Read more:

Making Your Own Hydroponic Nutrients