Hydroponic Tomatoes: How To Easily Grow Tomatoes Hydroponically

  • By: SFUAA NWB
  • Date: June 22, 2022
  • Time to read: 13 min.

Tomatoes are one of the most popular food items all around the world, and for good reason! These fruits are incredibly diverse and can be used from anything to soups to sandwiches.

However, growing tomatoes isn’t the easiest thing in the world, especially if you’re new to gardening!

Hydroponic Tomatoes: How to Easily Grow Tomatoes Hydroponically
Hydroponic Tomatoes: How To Easily Grow Tomatoes Hydroponically

To make things super easy and get the best results you could hope for, why not try growing them hydroponically? 

Hydroponic gardening is the science (and art) of being able to grow plants without using soil. The nutrients that plants need is fed to them via the water they are grown in.

As a result, this is a pretty clean way of growing your favorite plants, and the risk of many diseases is reduced. 

If you want to find out how to grow tomatoes hydroponically, just keep reading! We’ll be going through everything you need to grow hydroponic tomatoes successfully.

Before you know it, you’ll have some delicious fruit to pick off and use for whatever you want! If that sounds appealing, all you need to do is follow the steps outlined below.

You don’t regret it, we promise you that!

How To Grow Hydroponic Tomatoes – A Step-By-Step Guide

Overview

  1. Decide On a Hydroponic System
  2. Decide Which Good Growing Medium You Want to Use
  3. Pick Your Fertilizer (Nutrient Mix)
  4. Decide Which Garden Lights You Will Use
  5. Decide if You Will Use a Trellis
  6. Purchase Tomato Seedlings
  7. Prepare the Nutrient Solution
  8. Double-Check the EC and pH Levels
  9. Connect Your Kit
  10. Wash Your Growing Medium
  11. Place the Growing Medium Into the Mesh Pots
  12. Plant the Tomato Seedlings
  13. Set the Timer
  14. Get the System Working
  15. Take a Break!
  16. Maintain the Hydroponic System
  17. If You Need to, Keep Your Tomato Plants Short
  18. Cut the Suckers Off
  19. Tie Your Tomato Plants to the Trellis for Support
  20. Check for Any Diseases or Pests
  21. Harvest Your Tomatoes and Enjoy!

Step 1 – Decide On A Hydroponic System

The type of hydroponic system you choose will depend on how much electricity you can afford to use, the space it needs to cover, and how much water will be needed.

There are a number of super cheap systems available, and ones that are a lot more expensive.

Thankfully, there are systems available that will suit every area of space you might need to cover – from very large to pretty small.

Both a deep water culture system and aeroponics system are good choices, but this is largely down to personal choice.

Looking at deep water systems on the market, many of them are marketed as being great options for tomatoes and other similar vegetables, though! 

If you have a particularly large place that you need to cover, a good option would be the Dutch Bucket System, which is similar to the Drip System.

In this system, each plant is grown in its own container. 

Step 2 – Decide Which Good Growing Medium You Want To Use

This doesn’t apply if you are using an aeroponic system. For other systems, however, a growing medium should be used to get the best results.

This growing medium needs to be something that will be able to hold onto nutrients, water, and air. 

A good option would be to use expanded clay pellets, since they are common and cheap. You will easily be able to get your hands on them at any garden center you visit.

If you don’t want to use that, however, you can easily use other materials. These materials include coconut coir or vermiculite or a vermiculite and perlite mix.

All of these options are great for absorbing air and liquids, meaning they work well with hydroponic growing. 

Step 3 – Pick Your Fertilizer (Nutrient Mix)

Water might be the main ingredient in this growing method, but you still need nutrients or fertilizer!

Plants will be growing in a nutrient solution that is made up of water and nutrients, and those nutrients need to be supplied.

In particular, tomato plants do well when they get a lot of nutrients, because they tend to produce a lot of fruit. 

When you are looking for a nutrient mix for your tomato plants, it should be something that’s organic and specific to tomatoes.

Not only that, but fertilizer for tomatoes should have a nitrogen content that’s pretty low.

When it comes to the nitrogen, phosphorus, potassium rating (NPK rating), it should be something along the lines of 15-30-20, 5-15-15, or 10-20-20.

Step 4 – Decide Which Grow Lights You Will Use

This isn’t an issue if you live somewhere there there’s plenty of sun all the time. Grow lights are only necessary when you want to grow plants indoors or don’t get a lot of sunlight.

It’s popular to use spaces such as garages or old buildings for growing plants, so if you’re doing that – get grow lights!

Using regular lights isn’t good enough for plants. In order for a light to be of any use to a plant, it has to cover the red and blue spectrum, which is what plants require in order to grow.

The best grow light will cover the full spectrum, consume little energy, don’t heat up, and will last a long time.

A number of great lights even have timers that come with them, so you can mimic a 24-hour cycle. 

You can use LED grow lights and alter the amount of blue and red light the plants get at various points in their growth.

When a plant is young and is first growing leaves, they will need more blue light. When they blossom and grow fruit, however, they will require more red light to thrive.

Step 5 – Decide If You Need A Trellis

Most tomato plants will need some kind of support as they grow, which is where the trellis comes in. A number of hydroponic growing kits come with trellis, but this isn’t always the case.

If your kit doesn’t come with a trellis, you can support the plants by simply using sticks or poles and attaching (typing) your plants to them.

Alternatively, you can just keep your plants low by either pruning them regularly, or selecting a variety that’s short.

Step 6 – Grow Or Purchase Tomato Seedlings

Step 6 - Grow Or Purchase Tomato Seedlings
Hydroponic Tomatoes: How To Easily Grow Tomatoes Hydroponically

Finally, you can buy the seedlings! This can be fun, but also stressful. Since there are so many varieties to choose from, you will need to take some time to find out which is your favorite.

Take into consideration the plant height, too, as the space you have will impact how big they should grow.

It’s important to note that seedlings for hydroponic growing shouldn’t just be bought from a nursery like you would any other plant.

Because of the growing method, seedlings need to be bought from a hydroponic store. If you get seedlings growing in potting mix, the dirt will simply clog the pumps, and the plant could die. 

Make sure the seedlings are healthy – make sure they have at least three sets of leaves and are 5-inches tall at minimum.

Their stems should be green and strong, and overall healthy looking. If you are going organic, make sure that the seedlings are organic, too.

The easier and cheaper option may be to simply grow your own seedlings from seeds. This should be done hydroponically, too, and no dirt should be used.

Growing your own plants from seedlings is likely to save money and be less stressful, which is why many people prefer to go with this method. 

Step 7 – Prepare The Nutrient Solution

Now comes the time to mix your fertilizer and water. Depending on the nutrient solution, you will need to mix in various amounts of the solution with the water.

There will be a label on the bottle to tell you how many milliliters should be added to every gallon of water. 

Be sure to wait for the nutrient solution’s temperature to be at room temperature. This is either 65 degrees Fahrenheit, or 18 degrees Celsius. When it reaches that temperature, it can then be fed to the plants. 

Step 8 – Double-Check The EC And pH Levels

Measuring the electric conductivity (EC) and acidity (pH) levels of the solution are incredibly important. The majority of kits will have an EC and pH meter incorporated into them, but this may not always be the case. 

The PH of a solution is best at 6.0 – 6.5 for tomatoes, while the EC level should be somewhere between 2.0-5.0 for the best results. Always keep an eye on these two levels when growing any plants, especially tomatoes. 

Step 9 – Connect Your Kit

Next, it’s time to finally connect the hydroponic kit! This is likely to vary depending on where you got the kit, so be sure to follow the instructions given.

Most of the time, assembling the kit should be relatively easy and straightforward. However, if the kit of made of elements that are more discrete, you will need to ensure that:

  • The air pump is plugged into the mains
  • The air stone is in the (middle of the) reservoir
  • The timer is connected to the mains
  • The water pump is plugged into the timer (but don’t switch it on yet)
  • The fetching hose of the pump is at the reservoir bottom
  • The irrigation hose is connected to the grow tank

Step 10 – Wash Your Growing Medium

Washing the growing medium will need to be done every time you decide to change crops. You will have to disinfect and wash the medium before first using it, too. Thankfully, you can easily go this with some alcohol and water, and it isn’t too much work.

Step 11 – Place The Growing Medium Into The Mesh Pots

After the growing medium has been sterilized with alcohol and water, it can be placed in the mesh pots.

Before doing this, however, make sure that you have allowed all the alcohol residue to evaporate. Once that has happened, you can fill mesh pots with the medium.

Step 12 – Plant The Tomato Seedlings

This step isn’t very different to how you would typically plant seedlings in regular soil.

The easiest way to get this step done is by planting the seedlings at the same time as the growing medium is added to the mesh pots.

All you need to be careful of is ensuring that there’s enough space for the roots of the tomato plants to grow. Make sure that the growing medium covers the roots of the plants and the base of them stem.

Step 13 – Set The Timer

This is an important step for all hydroponic systems except deep water culture.

While lots of kits will come with timer settings laid out in the instructions, there are factors that may affect how long they actually need to be on. These who points are:

  • Day and night times – irrigation is typically not required at night unless it is extremely hot. Plant metabolism changes dramatically at night, so even if the weather is extreme, the plants will require less nutrient solution and fewer irrigation cycles. 
  • Weather conditions – hot and cold weather requires you to be pretty flexible with timing.

Depending on the hydroponic system you decided to use, the irrigation cycles will also be different.

If you’re using an ebb and flow system, drip, or aeroponics system, there will be drastic differences. Let’s take a quick look at them below:

  • Ebb and flow system – a total of one and a half hours of irrigation will happen during the day, or either 10-15 minutes every hour. In hot and dry weather, one or two night cycles of 10-15 minutes will also be required.
  • Drip system – incredibly flexible, but start at 10 minutes and take a look at the amount of nutrient solution that is still in the growing medium after around 50 minutes – then adjust from there on. Irrigation should be suspended at night unless it’s extremely hot. If this is the case, only one or two cycles will be needed.
  • Aeroponic system – a 3-5 second cycle every 5 minutes is recommended. These short cycles are very flexible, but should once again be suspended at night unless weather conditions are very hot and dry.

Step 14 – Get The System Working

Finally, you can switch the whole system on! This can usually be done by switching just one button, but make sure that the water and air pumps are on and working, just to be sure.

Remember to check all the lights if they are a key part of the process for your growing experience. 

Before you breathe a sigh of relief, check every section of the system and make sure it’s all running as it should.

Chances are it is, but it’s always better to be safe than sorry. Especially after you’ve put in so much time and money into your project.

Step 15 – Take A Break!

Hydroponic Tomatoes: How to Easily Grow Tomatoes Hydroponicallys
Hydroponic Tomatoes: How To Easily Grow Tomatoes Hydroponically

Now is the time to sit back and relax. The hard work is done for the most part, and you should enjoy the moment.

Go soak up some sun if it is a bright day – you deserve it! From now on, all you will need to do is maintain the system and make sure everything continues to work as it should.

Step 16 – Maintain The Hydroponic System

You will have to set time aside to regularly check on the system. Typically, doing these checkups shouldn’t take more than a few minutes, but always be prepared to spend some time down there.

You will need to check the EC and pH levels of the system every 3 days minimum. You will also need to check for any algae and clogs in the system at least once a week. 

If the EC level is too high in the system, all you need to do is add water to the whole system. If it’s too low, it’s time to change the nutrient solution.

When it comes to clogs or algae in the system, you will likely notice that there is an issue when you do your routine checks.

If this happens, simply clean out the system and get rid of anything that might be obstructing it.

Step 17 – If You Need To, Keep Your Tomato Plants Short

This is an important step if you have no or very limited head room in the space where you are growing your tomatoes.

If you accidentally bought tomato plants that grow tall, pruning them is a key step in making sure that the whole system works well and doesn’t get too crowded.

To do this, you just need to follow three simple steps:

  • Get a sharp pair of scissors or a similar time to use
  • Disinfect the blade
  • Cut the main stem of the plant, but be sure to leave two buts below the area where you cut

Doing this will ensure that your tomato plants stay low. Pruning like this will also encourage the plant to grow sideways instead of up, which is exactly what you want (hopefully)!

While hydroponic tomatoes are typically smaller than tomatoes that are planted in soil, they can still get pretty big, so keep an eye on them!.

Step 18 – Cut The Suckers Off

Suckers are branches that grow from the main stem and branches. They look like their own tiny plants, and end up stealing a lot of energy from the main plant’s higher branches.

We don’t want that, because the higher branches are typically the part of the plant that will produce the most fruit, and we want those!

When you cut off these suckers, you are allowing the main plant to keep its energy and put it into creating fruit.

This helps them stay strong and tall, and reduces the lower branches from growing too much and becoming messy.

All you need to do to cut these suckers off is use a sharp blade like you would with pruning, and cut it off at the base. 

Step 19 – Tie Your Tomato Plants To The Trellis For Support

Since tomato plants can’t grow straight up by themselves, they need a little help from you. To help them, you will need to use your trellis, or even a pole or stick, and tie them to it.

If you don’t do this, the plants will bend and grow very low, which typically is not what we want, even if there’s no soil involved in hydroponics. 

Allowing the plants to grow like this is made worse when the plant finally starts producing fruit. The weight of the fruit can lead to more bending.

If this were to happen with regular gardening, the fruit would start to rot when it comes into contact with the soil.

While this isn’t an issue in hydroponics, the fact that the plants can still break from the weight is not ideal.

To combat this issue, you can use rope, string, or a wire to tie plants to poles. There are some important things to remember when you’re doing this:

  • NEVER tie branches for support, only tie the main stem of the plant.
  • Keep the ties loose, or else you might damage the plant as it continues to grow or moves a little 
  • Always tie them before the fruit. The best time for tying is when they start to flower
  • You need to continue to tie the plant for support as it continued to grow

Step 20 – Check For Any Diseases Or Pests

Although hydroponic plants are usually much healthier than plants grown  in soil, they can still experience diseases or pests.

This isn’t as much of an issue, but it’s still something to keep an eye out for. Watch out for dark spots on leaves and stems, as well as noticeable lacerations on stems.

If a plant is diseased, they tend to have brown lesions on the leaves and stems.

If you notice that there are pests or diseases present in your plants – don’t worry! Even if you’re working organically, there are options.

Using things like neem oil or some essential  oils will solve most of the issues you can experience. Avoid using chemicals on your plants.

Step 21 – Harvest Your Tomatoes And Enjoy!

The time has come for you to harvest your bounty! You should start to notice tomato fruit forming on the plants within a month of planting seedlings. This can vary, of course, depending on the climate and other factors. 

Avoid picking green tomatoes, since they are usually less flavorful. To get the best experience possible with your tomatoes, pick them when they are beautiful and red.

Those are the ones that will make you fall in love with tomatoes all over again. You can then use them however you wish! 

Final Thoughts

Growing tomatoes hydroponically is a pretty easy and straightforward process, but it can have its challenges.

Hopefully this post has made things a little easier for you, and you now feel well equipped to try it out yourself. If you do give it a shot, let us know how it went. Good luck!

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