Best Hydroponic Fertilizer For Tomatoes: 10 Formulas Compared

#1 · Best Overall

1. MasterBlend Tomato Fertilizer

• Form: Powder
• Weight: 16 oz

Best for: Bulk tomato fertilizer powder.

Why it ranks #1: Its 4-18-38 powder is explicitly for tomatoes and hydroponic vegetables, is 100% water-soluble, and contains trace minerals.

MasterBlend’s water-soluble 4-18-38 powder is explicitly identified for tomatoes and peppers, giving vegetable growers a crop-specific ratio in a concentrated dry form. The listing offers 1-, 5-, and 25-pound quantities, which lets buyers select among stated package sizes for their growing plans.

The 4-18-38 formula and water-soluble powder form provide a clear starting point for hydroponic or garden use, as the product description names both settings. MasterBlend says the fertilizer contains trace minerals, adding a stated nutrient component to the main ratio. Its concentrated format is described as easy to use, while the listed quantity choices range from one to 25 pounds. The accompanying description recommends using it together with magnesium sulfate, so it is not presented as a standalone complete recipe.

Skip it if you want a liquid hydroponic feed rather than powder; GARDENWISE Hydroponics Nutrients is listed as a liquid formula.

Tomato and pepper growers comfortable mixing a concentrated powder may value the soluble 4-18-38 format and quantity options. The description recommends magnesium sulfate alongside it, a relevant consideration for planning a complete feed.

Listed on Amazon as: MasterBlend 4-18-38 Tomato & Vegetable Fertilizer – Bulk 1, 5 or 25 Pounds (1 Pound)

#2 · Tomato Formula

2. Cz Garden Supply 4-18-38

• Form: Powder
• Weight: 5 lb

Best for: Soluble tomato-garden powder.

Why it ranks #2: The 4-18-38 water-soluble powder is labeled for hydroponics and tomatoes, though the supplied listing gives limited mixing detail.

A water-soluble 4-18-38 powder labeled for tomatoes, peppers, and leafy greens offers a clearly identified crop-and-ratio combination. Cz Garden Supply also states that the concentrated product makes 1,000 gallons, giving growers planning large batches a specific yield claim to weigh against their needs.

The 4-18-38 ratio is the central specification, while the title explicitly names tomatoes along with peppers and leafy greens. Because the product is 100% water soluble and supplied as powder, its stated form is for mixing into water rather than applying as a ready-to-use liquid. The title also says the concentrate makes 1,000 gallons, a useful planning figure for larger growing operations. The supplied details do not specify a complete mixing recipe or added nutrient components.

Skip it if you want a stated liquid dilution routine for weekly feeding; Farmer's Secret Hydroponic Booster lists a teaspoon per gallon.

Growers seeking a soluble 4-18-38 powder for tomatoes and other listed crops can use its stated large-batch yield when planning. The supplied information lacks a mixing recipe, so it may not suit buyers needing one.

Listed on Amazon as: 4-18-38 Fertilizer Made in USA – 100% Water Soluble Plant Food for Hydroponics and Soil Gardens – Tomatoes, Peppers & Leafy Greens – Super Concentrated – Makes 1000 Gallons!

#3 · Liquid 4-18-38

3. EZ-gro 4-18-38 Nutrients

• Form: Liquid

Best for: EZ-gro nutrient-combo users.

Why it ranks #3: This liquid 4-18-38 is intended for tomatoes and hydroponics, but its complete solution requires calcium nitrate and liquid Epsom salt.

A liquid 4-18-38 fertilizer that can be paired with EZ-gro calcium nitrate and liquid Epsom salt gives tomato growers a defined route to a complete nutrient solution. The product is also identified for soil-based applications, allowing consideration beyond hydroponic setups.

EZ-gro describes the 4-18-38 liquid as one component of a solution, used with its calcium nitrate and liquid Epsom salt. The listed companion products supply named calcium, magnesium, and sulfur, so buyers can plan a multi-part nutrient workflow rather than treating this item as the entire combination. The formula is identified for both hydroponic and soil-based use, broadening its stated application. Buyers should note that the complete solution relies on the specified additional EZ-gro components.

Skip it if you want a single powder rather than a multi-part liquid combination; MasterBlend 4-18-38 is a water-soluble powder.

Tomato growers already assembling EZ-gro nutrients may appreciate the stated path to a complete solution and soil-use option. This 4-18-38 alone is not presented as the full combination, so account for its named companions.

Listed on Amazon as: EZ-gro 4-18-38 Hydroponic Nutrients for Tomatoes, Peppers & Leafy Greens | Hydroponic Plant Food Suited for Hydroponic and Soil Based Applications | Liquid Plant Food

#4 · Hydroponic Liquid

4. Farmer's Secret Hydroponic Booster

• Form: Liquid
• Weight: 11.2 oz

Best for: Reservoir and foliar hydroponics.

Why it ranks #4: Its 4-11-8 liquid is made for hydroponic or aeroponic systems, with directions for weekly reservoir feeding at one teaspoon per gallon.

A 4-11-8 liquid booster with instructions for reservoir, foliar, or combined application gives hydroponic growers multiple stated feeding routes. Farmer’s Secret lists use with any hydroponic or aeroponic system and provides a one-teaspoon-per-gallon dilution for most systems.

The 4-11-8 formula is identified for herbs, vegetables, and fruits, making it relevant to tomato growers within a wider crop mix. A weekly schedule runs throughout the growth cycle, and the label directs users to add the diluted feed to reservoir water, spray leaves, or combine those methods. For most systems, the product specifies one teaspoon per gallon; it also notes that a pod of about 0.25 gallons takes 0.25 teaspoons. That pod guidance can help translate dosing to smaller reservoirs.

Skip it if you need a tomato-only formula applied to soil weekly; Farmer's Secret Tomato Booster lists tomato-specific soil or foliar use.

Hydroponic tomato growers wanting reservoir and foliar options can use its stated dilution and weekly schedule as a starting point. Check the system-specific needs, since the one-teaspoon rate is given for most systems.

Listed on Amazon as: Farmer's Secret Hydroponic Booster Fertilizer – Super Concentrated 4-11-8 Formula – Use with Any Hydroponic or Aeroponic System – Great for Herbs, Veggies, Fruits, and More (32oz)

#5 · Three-Part System

5. General Hydroponics Flora Series

• Form: Liquid
• Weight: 8 lb

Best for: Adjustable stage-by-stage feeding.

Why it ranks #5: The hydroponic set covers growth and fruiting nutrients through FloraGro, FloraBloom, and FloraMicro, with separate stated N-P-K ratios.

Three separate liquids—FloraMicro, FloraBloom, and FloraGro—let General Hydroponics users custom-blend nutrients for plant type and growth phase. For tomatoes, the system offers a way to adjust the feeding mix as plants move through growth and fruit development, rather than relying on one fixed formula.

Each part has a named role: FloraMicro supplies nitrogen, calcium, and trace minerals; FloraBloom provides phosphorus, potassium, magnesium, and sulfur for flower and fruit development; and FloraGro contributes to the system’s blend. The supplied directions list distinct N-P-K ratios for all three and call for custom blending by plant type and phase. That flexibility can suit tomato growers managing changing needs, but it requires handling and combining three separate liquids rather than using one bottle.

Skip it if you want a single-feed formula with a stated weekly dose; Farmer's Secret Hydroponic Booster lists one teaspoon per gallon.

Tomato growers comfortable measuring separate nutrients may value the ability to adapt blends by growth phase, including fruit development. This three-part system adds mixing steps, so it is less suited to buyers seeking one ready-made feed.

Listed on Amazon as: General Hydroponics Flora Series: FloraMicro, FloraBloom, FloraGro – 3-Part Hydroponic Nutrient System, 1 qt. Bottles

#6

6. GARDENWISE Hydroponics Nutrients

• Form: Liquid
• Weight: 8 oz

Best for: Mixed home hydroponic gardens.

Why it ranks #6: Its 4-3-6 liquid is formulated for hydroponics and names tomatoes among suitable crops, but provides less tomato-specific detail than higher-ranked options.

A 4-3-6 liquid formula paired with chelated micronutrients gives GARDENWISE a broad home-garden role, naming tomatoes alongside strawberries, lettuce, herbs, and houseplants. Its stated compatibility with hydroponic and aeroponic systems lets growers use the same plant food across several indoor growing setups.

The 4-3-6 balance is presented for growth, foliage, blooms, and harvests, which suits a household growing more than tomatoes alone. GARDENWISE also identifies fully chelated micronutrients in its formula, giving buyers a named nutrient component beyond the N-P-K ratio. The product is explicitly intended for hydroponic and aeroponic systems, so it can serve those two types of home setups. Its 8-ounce bottle is a compact format, though the supplied details do not provide a dilution schedule.

Skip it if you need a listed dilution schedule for your hydroponic feed; Farmer's Secret Hydroponic Booster gives a teaspoon-per-gallon ratio.

Home growers mixing tomatoes with other indoor plants may value its broad crop list and hydroponic and aeroponic compatibility. Choose another option if a supplied mixing rate is essential to your routine.

Listed on Amazon as: Liquid Plant Food – Hydroponics Nutrients for Indoor House Plants, Tomato, Strawberry, Lucky Bamboo, Lettuce, Vegetable Garden & Herbs – Aero Nutrients Liquid Fertilizer for All Growing Systems (8 oz)

#7

7. FoxFarm Grow Big Hydroponic

• Form: Liquid
• Weight: 1.3 lb

Best for: Hydroponic vegetative growth.

Why it ranks #7: This liquid 3-2-6 concentrate is designed specifically for hydroponics and vegetative growth, making it less tailored to tomato fruiting.

A 3-2-6 liquid concentrate formulated specifically for hydroponic systems gives tomato growers a nutrient option focused on vegetative growth. FoxFarm says its formula supports plant size and structure and is quickly absorbed, making it a fit when you want a liquid feed aimed at early leafy and structural development.

The hydroponic-specific formulation helps distinguish this from general-purpose plant food, while the 3-2-6 ratio gives buyers a concrete nutrient profile to work with. Its liquid concentrate is directed to use at 2–3 teaspoons per gallon beginning the first week, a stated dilution that makes routine feeding straightforward. FoxFarm also lists micronutrients and earthworm castings, adding those named components to the formula. The focus is vegetative growth, so consider that emphasis when planning feeding for fruiting tomatoes.

Skip it if you want one product explicitly covering changing growth stages; General Hydroponics Flora Series offers three parts for custom blends.

Tomato growers seeking a liquid hydroponic feed for vegetative growth can consider this 3-2-6 concentrate. Its stated use begins the first week, but buyers wanting a stage-adjustable three-part system should look elsewhere.

Listed on Amazon as: FoxFarm Grow Big Hydroponic Plant Food – 3-2-6 Liquid Plant Fertilizer for Lush Vegetative Growth in Hydroponic Systems – Liquid Concentrate with Earthworm Castings & Micronutrients – 1 Pint

#8

8. Haligo A & B Nutrients

• Form: Liquid

Best for: Indoor A-and-B system growers.

Why it ranks #8: The A-and-B liquid nutrient set is described as compatible with indoor hydroponic systems and suitable for vegetables, but does not specifically name tomatoes.

A two-part A-and-B nutrient format supplied as an eight-pack gives Haligo indoor growers multiple nutrient portions for hydroponic systems. The listing names Aerogarden compatibility and broader indoor hydroponic-system use, making it a candidate for tomatoes grown in compatible countertop or indoor setups.

Haligo identifies its plant food as an A-and-B hydroponic nutrient set and states compatibility with Aerogarden and a wide range of indoor hydroponic grow systems. That stated system range can help buyers keep a nutrient option for indoor setups, while the eight-pack format includes two bottles plus six additional A-and-B packs according to the listing. The product is presented for indoor or potted plant growth. The supplied details do not specify a tomato-specific ratio or dosing schedule.

Skip it if you need a tomato-specific ratio and weekly dilution directions; Farmer's Secret Tomato Booster gives a 3:8:7 ratio and dose.

Indoor growers using an Aerogarden or another compatible hydroponic system may value the A-and-B format and listed supply. Tomato growers needing a specified ratio and feeding dose should choose a product with those details.

Listed on Amazon as: Hydroponics Nutrients for Aerogarden(800ml in Total), Plant Food A & B Hydroponics Supplies, Indoor Plant Fertilizer for Hydroponics Growing System, Hydroponic Solution for Vegetables Thrive

#9

9. Farmer's Secret Tomato Booster

• Form: Liquid
• Weight: 2 lb

Best for: Weekly tomato garden feeding.

Why it ranks #9: Its 3:8:7 formula is specifically for tomatoes and includes iron and calcium, but the directions describe foliar or soil application rather than hydroponics.

A 3:8:7 formula fortified with humic acid, iron, and calcium gives Farmer’s Secret Tomato Booster a tomato-specific nutrient profile. The label directs growers to dilute two teaspoons per gallon and apply weekly throughout the plant’s life cycle, providing a defined routine for garden tomatoes.

The product is formulated for all tomato varieties and described for use throughout their life cycle, making its stated scope broader than a single growth stage. Its dilution instruction—two teaspoons per gallon—translates the concentrated liquid into a repeatable weekly routine. Farmer’s Secret also identifies humic acid, iron, and calcium as fortifying components alongside the 3:8:7 ratio. The verified facts allow either foliar or soil application, so growers can choose between those stated delivery methods.

Skip it if you feed a mixed hydroponic garden and want a product listed for herbs and fruits; Farmer's Secret Hydroponic Booster covers those crop groups.

Tomato growers seeking a concentrated liquid with weekly directions and foliar or soil application options may find its routine clear. Its stated focus is tomatoes, so mixed-crop hydroponic growers should consider a broader-listed feed.

Listed on Amazon as: Farmer's Secret Tomato Booster Fertilizer – Super Concentrated – 3:8:7 Ratio Fortified with Humic Acid, Iron and Calcium – Grow More Tomatoes (32oz)

#10

10. FoxFarm Grow Big Liquid

• Form: Liquid
• Weight: 2.7 lb

Best for: Vegetative growth across crops.

Why it ranks #10: This 6-4-4 liquid names tomatoes and vegetables, but the supplied information does not identify it as a hydroponic fertilizer.

FoxFarm’s 6-4-4 liquid concentrate is presented for fast nutrient uptake and vegetative growth, with tomatoes named among its suitable crops. Its description links feeding to plant size, structure, and fruit, flower, and bud development, offering a broader garden-use profile than a tomato-only formula.

The 6-4-4 ratio gives buyers a specific nutrient profile, while the listed crop range includes roses, tomatoes, and vegetables. FoxFarm describes quick nutrient uptake for both newly sprouted and established plants, which can fit a garden with plants at different stages. Its liquid concentrate is convenient for liquid feeding, though the supplied directions do not give a dilution rate. The description emphasizes vegetative growth and development, so growers should weigh that stated focus against their fruiting-stage feeding needs.

Skip it if you need a stated hydroponic mixing ratio; FoxFarm Grow Big Hydroponic Plant Food lists 2–3 teaspoons per gallon.

Gardeners feeding tomatoes alongside roses or other vegetables may appreciate its broader crop list and stated fast uptake. The supplied information gives no mixing rate, so growers who require a defined hydroponic dose may prefer another product.

Listed on Amazon as: FoxFarm Grow Big Liquid Plant Food – 6-4-4 House Plant Fertilizer for Lush Vegetative Growth, Fast Nutrient Uptake for Roses, Tomatoes & Veggies – Quart Size Concentrate