How to Grow Hydroponic Tomatoes

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By Jeff Hale

Tomatoes are an easy crop to grow, and you can enjoy them in multiple ways. But a significant issue is that tomatoes can be challenging to separate from areas they’ve been previously grown in. Their fruit is incredibly efficient at establishing new plants.

If you want to use an area for another crop later on, you should steer away from planting tomatoes during the year. But if you grow them in a hydroponic unit you won’t have any of those problems.

But what type of hydroponic unit should you use for tomatoes? What spectrum of lighting do hydroponic tomatoes need? And what are optimal growing conditions for hydroponic tomatoes?

We’ll tackle all these questions and more in this article. Let’s first go through the optimal growing conditions for hydroponic tomatoes.

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Growing Conditions Hydroponic Tomatoes

While tomatoes are quickly germinated (taking only four days), they are prone to many problems. Whether it is mold or insects, they are delicate plants.

Technically, tomato plants are vines and can grow up to six feet tall with support. Initially, tomatoes originated from the western South American region all the way up to Central America.

Tomatoes are also technically a fruit and not a vegetable, and the fruit is considered a berry. As they originated in South America, they love warm to temperate climates.

They are a perennial plant but when grown in greenhouses or commercial setups can be annual.

In a nutrient sense, 95% of a tomato is water, containing 4% carbohydrates and less than 1% fat and protein.

If you consume 100g of raw tomatoes, you’ll be ingesting 18 kilocalories, and you’ll be getting a moderate dose of vitamin C.

What elements does a tomato plant need to tap into to achieve its best?

Developing Seedlings

Tomatoes are easy to germinate. Simply place the fruit into the soil, keep it moist, and wait around four days.

While this technique will produce many shoots, tomatoes hate to be crowded. Mother nature works in mysterious ways.

This means you’ll be required to thin out the seedling by snipping out the weaker and smaller shoots.

If you don’t thin out the crop, you’ll be left with a plant that is stressed, which will result in a diseased plant later on.

Starting from an early age, you will want to remove the lower branches. This pruning will begin when the plant has reached a height of three feet.

Also, pinch the small suckers that develop in between the branches. There is a balance to be made when pruning your tomato plant, but essentially you want to thin out the leaves so that the sun can reach the ripening fruit but allow for photosynthesis.

Learn more about starting seeds for hydroponics


As a temperate plant, tomatoes require warmer conditions. You can grow tomatoes between 55°F to 85°F. But the goldilocks zone is 58°F – 79°F.

At night, you want to ensure that the temperature doesn’t drop below 55°F.

This wide variation in temperature requirements varies between breeds of tomatoes. Depending on the family of tomatoes, you could have a fruit that requires higher or lower temperatures.

If you are setting up your hydroponic unit indoors, you’ll want to be able to maintain this high heat throughout its development.

As tomatoes love warmth, your growing medium will also need to be monitored. You can boost the temperature by wrapping the grow medium in plastic and putting a heat source on it.


Tomatoes require loads of direct sunlight. You should program your lighting rig for 14 to 18 hours a day.

When growing seedlings under a fluorescent grow light, you want to ensure they don’t turn into a spindly plant. Nothing worse than a floppy tomato vine.

Make sure the light is only a few inches from the rig to prevent the vine from growing too long.

Air Ventilation

As we’ve mentioned, tomatoes are prone to diseases. One of the significant problems is mold. Tomatoes need to grow with excellent ventilation.

You can rectify this potential issue by turning on a fan twice daily for 5 – 10 minutes. We’d recommend setting up a fan that operates on a timer.

If you’re not interested in installing a fan, you can gently brush the plants for a few minutes a day.

Planting The Seedlings

With tomato seedlings, you want to ensure that you bury the plant’s stem into the growing medium.

Tomatoes can develop additional roots off their branches, which creates a healthier plant.

Once the plants are correctly potted, you’ll want to mulch. Mulching will save water as well as retain heat.

Another reason it is good to mulch tomatoes is they are thirsty plants and require loads of water.

pH and Electrical Connectivity (EC)

As you’ll be growing these in a hydroponic unit, you will need to know what is the optimum pH for the solution and EC.

Your water solution’s pH range should be between 5.5 – 6.5. For the optimum level, you will keep the pH levels within this narrow scope.

With EC, you’ll have more flexibility, between 2.0 – 5.0. It’s essential to monitor these levels to ensure your plants can tap into the nutrients in the solutions, as tomatoes are nutrient hogs.

Nutrient Solution

Tomatoes need loads of nutrients to grow healthy and plump fruit. While you might want to go for an organic solution, a specially formulated blend is better.

The reason for this is that organic fertilizers can increase the chances of root rot or nutrient lockout.

You can purchase pre-blend hydroponic nutrients, like the MASTERBLEND 4-18-38 Complete Combo Kit Fertilizer Bulk. Just follow the instructions on the packaging, and you’ll be ready to go.

For more nutrient options check out our buying guide: Best Hydroponic Nutrients

Now, let’s talk about what you’ll need to grow tomatoes hydroponically.

What You’ll Need To Grow Tomatoes Hydroponically

Hydroponic System – Ebb & Flow or DWC

If you’re planning on growing hydroponic tomatoes, you will need to select a hydroponic method to grow them.

Tomatoes will be fine in deep water cultures (DWC), Ebb and Flow systems, Nutrient Film Technique (NFT), and aeroponics. They will take to any conditions as long as there’s plenty of water and nutrients.

We’d recommend going with an ebb and flow system as they are fairly simple to install and use, as well as allowing for the plants to reach their full potential.

Also, ebb and flow systems are easy to expand for experts and novices alike.

A system like the VIVOSUN Hydroponic Grow Kit, which is one layer with 36 plant sites, is exactly what you want and can be used for a variety of crops.

VIVOSUN Hydroponic Grow Kit, 1 Layer 36 Plant Sites 4 Food-Grade PVC-U Pipes Hydroponics Planting System with Water Pump, Pump Timer, Nest Basket and Sponge for Leafy Vegetables


And it is easy to set up, has a pump timer, and nest baskets/net pots.

Another method that might be fun to experiment with is the Dutch Bucket method, which is similar in technique to DWC mixed with a bit of ebb and flow. The difference is water from the reservoir bucket is dripped through multiple five-gallon growing buckets.

The water drains through the growing buckets’ substrate into a drainage line and flows back into the reservoir bucket that contains the nutrient solution.

If you want to purchase this system off the shelf you can purchase the DWC Hydroponic Bucket System from Bavnnro.

DWC Hydroponic Bucket System, Recirculating Top Feed Drip Hydroponics Growing System 5 Gallon Deep Water Culture Bucket System Kit for Herbs/Vegetables/Fruits(4 Bucket + Reservoir + Drip Kit)


This systems comes with everything you need to get started:

  • Growing Bucket
  • Reservoir
  • Air Stones
  • Air Pump
  • Top Feed Drip Irrigation Kit
  • Water Level Indicator
  • Drip Flow Adjust Knobs
  • Grow Medium – Packs Clay Pebbles

Experts will want to lean towards the Dutch Bucket system as it gives the grower more flexibility in producing the best tomato plants.

For more hydroponic system recommendations check out our guide: Best Hydroponic Systems

Grow Lights

While you can grow hydroponic tomatoes outdoors, it’s most likely you’ll be setting up indoors, which means you’ll need a light rig.

The type of light you choose will correlate with the size of your crop. We’d suggest using an LED light as it is easier to operate and install.

Also, they generally use less electricity and generate less heat.

The VIVOSUN VS3000 LED Grow Light is great as it uses high-quality Samsung Diodes and can be daisy-chained (you can link other units to it).

VIVOSUN VS3000 LED Grow Light with Samsung LM301 Diodes & Daisy Chain Driver Dimmable Lights Sunlike Full Spectrum for Seedling Veg & Bloom 300W Plant Grow Lamps for 3x3/4x4 Grow Tent


While it is more expensive than a simple houseplant unit, this will ensure your tomatoes reach their best potential.

For more options check out our buying guides: Hydroponic growing lights and Reflector hoods.


The next item you’ll want to install in your indoor grow area is a digital thermometer, which also measures humidity. Tomatoes are especially vulnerable to diseases and a big killer is mold.

During night time you want the humidity to be between 65% and 75% and during the day between 80% and 90%. High humidity at night will cause mold.

The next step to prevent diseases from taking hold of your plant is a fan. You need to make sure that the air is circulating around the growing area.

Now that you’ve gone through the shopping list let’s focus on how to grow your tomatoes hydroponically.

How to Grow Hydroponic Tomatoes

The first step in growing tomatoes is finding the correct location for the maximum exposure to light. If you’re growing indoors this is simpler than scouting the yard.

In homes that get little to no light, it might be best to mount your tomatoes to a high wall, catching as much light as they can.

While your plants will thank you for a good flow of air, strong gusts of wind will damage your tomatoes. Make sure that it is sheltered from the full force of mother nature.

Tomatoes love to be able to access as much water as possible. Your hydroponic unit will provide the optimum levels of water.

Depending on if you build a hydroponic system or purchase one, the assembly can be accomplished by following instructions or general know-how.

If you’re growing from seed or fruit, you will need to use the correct growing medium, and we’d highly recommend Rockwool.

While you can germinate seeds in the soil, transplanting them into a hydroponic unit risks the transfer of pathogens from the soil.

When growing in the perfect conditions you can expect your tomatoes to last 8-11 months. If you sprout your seeds in January this will take you to October. Germination is quick and shoots will appear in four days.

Pruning is key to keeping your tomatoes alive as their lower leaves need to be trimmed away and early flowers should be pinched off.

You can start pinching off flowers after a month or two.

And tomatoes will always need the support of a stake. So plan accordingly.

Tomatoes don’t need pollinators as they self-pollinate.

And like that, you’re ready to start growing tomatoes hydroponically.

Growing Hydroponic Tomatoes Successfully

There’s nothing that tastes better than your own homegrown tomato. And the simple act of walking through your grow area and picking what you need will transport you to a time and place forgotten in the hyper-modern world.

While using hydroponics is the most advanced method to grow tomatoes, it also promises to prevent them from infections, mold, and much, much more.

There’s no time like the present to start growing your own hydroponic tomatoes.