How to grow lettuce hydroponically

How to grow lettuce hydroponically

Do you want to know how to grow hydroponic lettuce? Are you curious about starting a hydroponics garden and need a simple 9-steps process? I’ve wanted to make this guide since I purchased my first kit here. If you want you can get something similar on Amazon.

And if you are asking why growing lettuce. Because the crisp, leafy green is easy to grow hydroponically and super versatile in the kitchen. If you are like me you want to grow your fresh salad. Instead of Store-bought salad greens with chemicals you need a new lifestyle. Check out the following system and tips I learned during this experience.


What is lettuce hydroponic?

Hydroponics is a form of farming that uses a nutrient solution root medium, rather than soil, to grow plants. According to treehugger . Lettuce (Lactuca sativa) is one of the most commonly grown hydroponic vegetables.

Is lettuce hydroponic good for you?

Yes, hydroponic lettuce has all the same health benefits as the soil-grown. It's a good source of vitamin K, essential for bone strength and  vitamin A good for the eyes. Since it’s up to 95% water, it can have a hydrating effect. 

How to grow hydroponic lettuce?

Learn how to grow hydroponic lettuce in under 15 minutes. The hydroponic system is easy to prepare and you have to try it at least once, right?

And now, put on your garden gloves and apron.

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Difficulty: Low

  • Cost: Economic
  • Preparation time: 150 minutes
  • Growing time: 6-8 weeks
  • Growing method: Hydroponic
  • Crop: Lettuce


Everything required for 1 hydroponic system

  • 1 hydroponic Box - 6 or more holes - 28x19x14cm (L x W x H)
  • 6 or more Net Cups 
  • 6 or more Rockwool Cubes, Soil pot or growing medium like sponges 
  • 1 Air Pump
  • 1 Tube Kit 100cm long with the air stone
  • 1 Tweezer for your seeds
  • 1 Buoy so you know the level of your nutrients



Ok here is how to grow hydroponic lettuce Step by Step.

Step 1

Ok so start by soaking the lettuce seeds (or any other seeds > check later for tips) for 3-6 hours. Let it sit in a box with water overnight.

Step 2

Take all the sponges. Squeeze out the air. Rinse them off in the sink a few times in warm water. Let them sit in chlorinated water for two hours. After some time take the chlorine out and leave them in water overnight.

Step 3

Place the sponge cubes in a box or ice cream bucket and put the seeds near the top or 2-3 mm in depth.  Add just a little bit of water in it and until the seed has roots coming out of the bottom of this medium. If you are growing the seed from soil skip to Step 7 and read the tips on how to do it.

Step 4

Put the cups into the bottom of the tank. Pour the appropriate proportion of nutrient solution. The level of nutrient solution is about 2 cm - 0,7 in total or 2 ml - 0.07 ounces for every liter - 0.2 gal of water. 

Step 5

Put the planting box into a sunny place or with red growing lights. You can use 224-300 watt lights. Or you just put in your windowsill or a sunny window anywhere. Keep your box between 60-70 degrees F (15-21 C) because anything warmer it won't hold the oxygen in the water. The seeds will grow after about two weeks. Then remove the sponges with seeds from the tank. 

Step 6

Set the tube up. Took the air stone off. Enter the air hose through the hole on top of a smaller hole and then reconnect the air stone. It has a check valve so water can backflow the air pump. Then connect your air pump. Connect the power for oxygenation and ensure it for 8 hours every day. 

Step 7

Put the planting cup into the planting hole. Fill the tank with water just until the water hits the bottom of the net pot. It will keep the sponges moist. Later when you have plants with roots hanging down you can have a lower water level, like a 12.7 mm - half inch. Pour the nutrient solution in the water, about 2 cm - 0,7 in or 7 ml - 0.24 ounces for 3,5 liters - 0.9 gal of water. Check the tips for different watering nutrient solutions.

Step 8

Make sure the buoy is in the green position (safe area). When in the red position (alert area) you need to add nutrient solution. You can use a TDS meter which means Total Dissolved Solids with a digital reading. 

Step 9

After the plant grows, the level of nutrient solution should be reduced, which is beneficial to the plant's growth. Healthy roots should look nice and white. Otherwise if you had chlorine in the water or you used too much nutrients they'll turn brown. The plant should grow in three weeks. And in about five days roots will start coming down from the net pot.

how to grow hydroponic lettuce
Photo by Jatuphon Buraphon on


Per Serving: 

  • All-around hydroponic fertilizer about 2 cm - 0,7 in or 7 ml - 0.24 ounces for 3,5 liters - 0.9 gal of water. 


Is hydroponic better than soil?

Compared To Traditional Soil-Grown Crop Production, The Benefits Of Hydroponics Includes: Up to 90% more efficient use of water. Production increases 3 to 10 times in the same amount of space. Many crops can be produced twice as fast. Saving land that can be used for animals. With the use of technology it is possible to save labor. It does not use fertilizer, pesticide and therefore is friendly to the environment.

selective focus photography of green vegetables from how to grow hydroponic lettuce article
Photo by Soo Ann Woon on

Can I plant hydroponic lettuce in soil?

I have seen this question on the video A Great Hydroponic System For Beginners: Pathonor Hydroponic System and answered it. Since hydroponic lettuce grows with its roots directly in water, there's no need for soil. Instead if you want to grow medium both to help the seedlings sprout initially and also to provide physically for the roots as the plant continues to grow.

# Tips for making this growing seeds a little different

  • You can use  different types of seeds (also known as flax seeds) instead of lettuce seeds. If any of these plants die, please remove the plant and its roots in time.
  • Always use the right amount of nutrients. If you are growing seeds, read on the package how much they need. If you choose basil, that one needs 800 ppm (“parts per million”)  of the nutrient.
  • Measure the nutrient with a TDS meter which means Total Dissolved Solids with a digital reading. You could pretty much just use two teaspoons and that will bring it to 800. So if you don't want to buy a TDS meter you can just go off with that.
  • Simply add a little bit of nutrient at a time so you don't go over the amount that you want. Otherwise you'll burn the plant
  • If you are growing seeds in soil or any other medium when you have the first root, scoop it out and be careful with It.
  • Put the root into the water and swish it around until all the dirt is removed or as much as you can get off of the roots to have some bare roots.
  • Put roots in the growing medium sponge till they come off the bottom a little bit and add it into a little net puck and into the system
  • I'm using rock wool that comes in sheets of 20 or more with a one-inch hole which is perfect to put the seed inside. It sprouts a few days later and then I don't have to transplant anything.


To harvest the whole head of lettuce at once, either remove the entire plant by cutting from the roots or cut off all of the leaves at one time from the base of the plant.

If you plan on continuing your hydroponic lettuce garden, make sure you have replacement seedlings ready to replant into the system. 

Overall I think this is a good unit for 30 bucks and you can't beat that price. It comes with everything you need for beginners.

And if you ever wanted to try hydroponics this is a good kit to get. Ok so by now you should how to grow hydroponic lettuce. Anyway if you have questions I'll be happy to answer.

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I hope you enjoyed my instructional review and I remind you to find more articles on and recipes on

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