How to grow hydroponic tomatoes

If you want to learn how to grow hydroponic tomatoes then this article is for you! Growing tomatoes hydroponically indoors is a great way to grow your own food year-round. If you are growing plants indoors, you can have a lot of fun harvesting tomatoes in the winter!

Hydroponic gardening means growing plants without the use of soil. The plant roots are grown in nutrient-rich water. It is perfect for people who live in apartments or have limited space.

Tomatoes are a favorite food for many people and can be grown hydroponically with ease.

Many different types of plants can be grown hydroponically and there is a benefit to companion planting ie. putting plants together that support one another. However, this article will focus on tomatoes and discuss the basics of how to grow tomatoes hydroponically.

Tomatoes make a wonderful addition to a hydroponic garden. I don’t think that I would get any disagreement with the statement that the tastiest tomato is the one you grow yourself!

Hydroponic tomatoes are a great way to get fresh tomatoes in your diet. Luckily it doesn’t take very much to grow tomatoes hydroponically.

How to grow hydroponic tomatoes

Here are the 7 steps to grow hydroponic tomatoes.

1 – Decide on the type of system you will use

2 – Decide the type of tomatoes you want to grow

3 – Plant the seeds

4 – Water

5 – Nutrients

6 – Light

7 – Temperature

Step 1 – Types of Hydroponic systems

You have options when it comes to hydroponic systems. You can make your own hydroponic system or you can purchase one.

Here are some ideas for the best hydroponic system for purchase. And here are some ideas if you choose to go the DIY route.

Step 2 – Types of tomatoes to grow

What type of tomato should you grow hydroponically?

There are many varieties of tomatoes that can be grown hydroponically.

Tomatoes can be determinant or indeterminate.

Determinate tomato varieties usually grow as bushes and these are less ideal for indoor hydroponics.

Indeterminate varieties grow more like a vine and are better suited for indoor hydroponics.

If your growing space is limited then choosing a smaller variety such as a cherry tomato or grape tomato is a good option.

Step 3 – How to plant seeds

Plant your tomato seeds in a small container with hydroponic starter cubes or netting. If you have tomato seedlings that were grown in soil it is not a good idea to transplant them into your hydroponic system as they could be harboring unwanted pests that you don’t want to introduce into your system.

One advantage of purchasing a premade hydroponic system is that it comes with its own grow pods that make the process easy and convenient. However, if you go the DIY route then there are many choices available to purchase at a hydroponic store for a very reasonable cost.

  • Rockwool starter cube
  • Sand
  • Clay pebbles
  • Gravel
  • Perlite
  • Sawdust
  • Peat moss

It is very important that the material is not providing any nutrients to the plant. Also have three inches of depth at least so that it can support the plant as it grows.

Step 4 – Water

Tomatoes need an abundance of water to grow big and healthy. Since the plants are being grown in water it is very important to consider what type of water you are going to use.

Most people naturally ask can I use tap water for my hydroponic system. The issue with using tap water is what may be in your tap water.

If you live in a city it is not the best idea to use tap water and that is because many cities add chemicals to their water such as chlorine or chloramine which may be harmful to your plants.

Chlorine and chloramine are used in water to kill microbes such as harmful bacteria. Chlorine will break down in your water if you expose it to the sun for 24 hours. Unfortunately, this will not work as well for chloramine. To break down chloramine you can dissolve a Campden tablet in the water.

Another thing to ponder is if you live in an area with hard water. Hard water means that the water contains more minerals. It is easy to measure the TDS (total dissolved solids) of your water with an inexpensive TDS meter.

The thing to be concerned about with hard water is that it delivers an overabundance of minerals such as calcium and magnesium to your plants. While it’s true that plants need these minerals they only need them in smaller amounts.

If the TDS of your water is greater than 200-300 PPM that is too high for your plants.

Once you have removed harmful chemicals and overabundance of minerals from your water then it is safe to use your tap water.

An easy way to remove these chemicals and excess TDS is to use a water filter such as a reverse osmosis system.

If you don’t want to spend the money to purchase a reverse osmosis system then you could also use distilled water. Distilled water would not contain any of these unwanted elements.

If you are growing your tomatoes outside then using rainwater or collected stormwater is a good idea because it does not have any of the harmful chemicals that can be found in tap water. Just make sure that the pH of your water is in the correct range for tomatoes which is between 5.5 – 6.5.

Step 5 – Nutrients

Since growing hydroponically doesn’t use soil it just uses water as a growing medium you have to add the nutrients to the water

Some things to keep in mind about nutrient solutions. Tomatoes need a lot of water. Water is what makes juicy tomatoes juicy and who doesn’t like juicy tomatoes! This should be apparent because when biting into most varieties of tomatoes there is a lot of juice and water is required to make all that delicious juice!

Tomatoes are heavy feeders so the type of nutrient solution you use matters because the types of nutrients you add to your water is important. Most varieties of tomatoes need the following nutrients…

  • Nitrogen
  • Phosphorus
  • Potassium
  • Magnesium
  • Calcium
  • Trace Minerals

So you want to make sure that the nutrient levels of the liquid nutrient solution you use contain adequate amounts of these nutrients.

Additionally, tomatoes grow well in a pH ranging between 5.5 to 6.5 so you will want to be checking the solution you are growing your tomatoes in to make sure it is within this range.

Step 6 – Light

Tomatoes need an abundance of light to grow. If you are growing tomatoes inside, in order to give them adequate light it is best to place them in front of a window that gets a lot of sunlight throughout the day.

It may also be necessary to supplement natural light with artificial lights such as fluorescent bulbs or LED grow lights which can provide additional light.

If you purchase a hydroponic system then they will either come with LED lights built into the unit or you can purchase them separately you need them.

Tomatoes can do well with a minimum of 7 hours of light. Keep in mind that fully mature tomato plants in order to have maximum production need about 16-18 hours of light.

Step 7 – Temperature

Tomatoes require warm weather to thrive so keep that in mind when selecting a location for your hydroponic system. Temperatures between 70-79 degrees F (21-26 degrees C) work well for tomatoes


Tomatoes are an excellent choice for growing hydroponically. You can grow tomatoes indoors all year round and if you choose a smaller variety they can be grown in a smaller space so you can grow them indoors.

However, tomatoes and vegetables aren’t the only plants that can be grown hydroponically. Nonedibles such as succulents can be grown hydroponically, which can be a nice solution for those of us who may have a hard time remembering how often to water our succulents.

Having a hydroponic tomato garden can be fun for both the beginner gardener and for expert gardeners. 

Now that you have the information you need to grow your own hydroponic tomatoes, it’s time to get started! Just be sure to take all of these things into consideration and you will be on your way to a bountiful harvest. Enjoy!