Nutrient Guide: How to Grow Hydroponic Tomatoes Easily


Tomatoes are incorporated in many cuisines and dishes and are great to enjoy on its own as well. Unfortunately, fresh batches of tomatoes are a rarity during the colder months. Thankfully, with science and technology, humankind has already devised a way to go about this with the advent of hydroponic cultivation methods. For those unaware, it is the act of cultivating plants without the use of soil and instead, the use of nutrient solutions in water. 

Hydroponics allows for tomatoes to be cultivated and sold in your local mart all year around. Given the wide use of tomatoes in culinary, it is unsurprising that this particular food product is a top pick for commercial and home growers. 

Contrary to popular belief, the tomato is not an easy plant to cultivate hydroponically. Although there are many cases of home growers growing their own hydroponic tomatoes, it is not advisable for beginners to choose tomatoes as their first hydroponic plant to cultivate. Unlike the leafy greens, the tomato plant requires much more effort and attention to detail, which is easy for beginners to overlook. It is recommended that hydroponic beginners try their hand with crops such as lettuce, kale, or thyme which are much easier to deal with. Take time to amass experience and knowledge and you may want to try your hand at growing tomatoes after you have the necessary skills and confidence after some time.

Choosing between seeds and saplings 

Most growers agree that saplings are the easier option of the two to cultivate. However, tomato saplings that are grown outdoors are not suitable for hydroponic systems. This is because seeds that are grown in soil have a high chance of being contaminated by harmful organisms. These harmful agents spread extremely quickly. Just having one contaminated seedling is capable of destroying the entire crop. Hence, it is common practice for seasoned growers to choose to grow tomato seedlings instead. Those purchasing seedlings from their local gardening store or nursery should ensure that the seedlings are free from harmful bacteria and other microorganisms. 

Here’s a quick guide to growing your homegrown tomato saplings from seeds. Place the seeds in a tray of growing medium, such as rock wool cubes. Next, add some water with a pH level of about  4.5 to sufficiently wet the growing medium. Lastly, place the tray in a moist and damp area, ideally within the temperatures of around 20 to 25 degrees celsius, and cover the seeds. Wait patiently for around 10 to 14 days. In this time, the seeds should sprout and you are advised to immediately swap them into the hydroponic setup. This method is also adopted by those who wish to cultivate heirloom varieties which are rarely found as saplings in gardening stores.


Choosing determinate or indeterminate varieties

The key differences between determinate and indeterminate boils down to the vines of the tomato plant. The former has bush-like vines, and they spread and sprawl across the ground. The latter, on the other hand, have vines that grow vertically up.

The indeterminate tomato plants are capable of growing continuously. With the right support and care, these plants can continue to bear fruit endlessly. 

We recommend the determinate tomato plants for hydroponic growing and a space that is limited to a small indoor area.  This is because this variety grows up to a maximum of slightly beyond four feet, and is unlikely to take up too much space. One thing to note is that the plants usually exhibit a reduction in growth after they bear fruit. 

While the bush type tomatoes are troublesome to prune in a trellis structure, it is typically rather easy to do so with the vining type. All one has to do is select the preferred leader steam and further support its growth on the trellis.

For vining varieties, we recommend Brandywine, Matusalah, and Trust. Moskvich, Thessaloniki, and Brandywine Pinke are good choices for Heirloom varieties. Lastly, cherry tomatoes, plum tomatoes, and others are popular choices to grow for specialty varieties.

Growing requirements 

To grow healthy tomato plants, these are the growing requirements that you ought to achieve and provide.

Tomato plants ideally need to receive some light for a minimum of eight to ten hours daily. Varieties with high yield may require up to 18 hours of light. Tomato plants that are close to their mature stage should be given eight hours of no light. We suggest providing light of about 16 hours for the best fruit yields. 

The optimal temperatures for tomatoes are within the range of 18 to 25 degrees Celsius during the daytime.  For the night, anywhere between 12 to 18 degrees would suffice. Take note that any temperature beyond 90 degrees and below 50 degrees can harm the plants immediately. 

For the nutrient mix, it is best to get those specifically made for tomatoes, which are high in phosphorus, nitrogen, and potassium. The recommended pH and EC levels are between 5.8 to 6.3, and 2.0 to 3.5milliMhos respectively. Follow these recommendations and your plants should grow fine. 

The popular growing medium choices are expanded clay pellets, coco coir, rock wool, and perlite. Different growing medium best suits different hydroponic systems. For this guide, we will be specifically exploring the ebb & flow method, which is compatible with all the aforementioned growing mediums.

Hydroponic Tomatoes via Ebb and Flow Technique 

Before we begin, make sure that you have these items: A large reservoir tray with lid, a smaller tray for holding the plants, container pots for each of the plants, a submersible water pump, a timer, two PVC tubes – one of one and a half inch and another larger one. Besides these, you will also need a growing medium and tomato-specific nutrient mix as discussed earlier.

To start off, get the reservoir filled with water. The total amount of water you need will be double the total number of plants multiplied by 2.5. Next, punch holes onto the lid as this will allow the tubes to pass through. This lid will be helpful in preventing algae growth. 

Now, attach the smaller tray right above the reservoir. Make sure the tray has tall enough sides for this technique to work. Then, fix the water pump into the reservoir. We recommend using an adjustable pump so that you can toggle the output. With the two tubes, link up the tray, pump, and reservoir. At the bottom of the tray, drill two holes. The smaller of the two tubes will be used for the water inlet and connected to the pump. The remaining tube will be then used to channel excess solution out of the growth tray. 

Install filters on both inflow and outflow tubes to prevent any possible clogging. Once you reach this stage, try running the system to see if everything works fine. 

Now, on to placing the saplings in the individual pots in the growing media. Ensure the pots are spaced out evenly. Add the nutrient mix into the water and link up the pump to a timer. Run the motor for half an hour once every two hours. Make lighting arrangements for the plants to receive adequate light for growth. 

For maintenance, check the pH and EC levels of the water daily. You will need to change the water and nutrient mix weekly. Also, take note that more nutrients will be needed as your plant matures. Growing these vine-type tomato plants require you to prune the stems and you can consider installing support to ensure that the plant grows upright. 


Once flowers grow, pollinate them with your fingers gently. Prepare to harvest once 50 days have passed. Some cultivars may take up to 100 days though. 

In conclusion

We hope this article has helped to inform you of the essentials and necessary preparations to make for hydroponic tomatoes. Cultivating your own hydroponic plants can be extremely rewarding once you get the hang of the process. Cheers to growing your own hydroponic tomatoes!


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