Hydroponic Lettuce – Growing Tips And the Best Lettuce For Hydroponics

Leafy greens make some of the best choices for plants you can grow with hydroponics. They are easy to maintain and they thrive in hydroponic systems. 

Growing hydroponic lettuce might be one of the simplest veggies to grow without soil, but that doesn’t mean you don’t have to follow certain steps.

That’s why we are here to lead you through the process and recommend some of the best lettuce varieties to grow with this method. 

Also, we’ll lead you through some growing tips and the best systems for lettuce hydroponics.

Selecting the Best Hydroponic Lettuce Type To Grow

Choosing the varieties of lettuce to grow might be one of the most difficult choices for you to make, because the rest is pretty easy, haha. 

Luckily, almost any type of lettuce works well with hydroponics, but there might be a few species that thrive better than others. 

These are the main varieties that would be easiest to care for in your hydroponic garden:

• Loose-leaf lettuce

• Romaine lettuce

• Butterhead lettuce

• Iceberg lettuce

• Little Gem lettuce

With loose-leaf lettuce species, you will be able to pull out the leaves and new ones will regenerate in their place. 

It can be beneficial to go with a variety like that if you wish to extend the growing season. 

Also, Butterhead lettuces like Bibb lettuce work best for salad if you plan on growing your own healthy green veggies with hydroponics.

Another variety of butterhead lettuce is the Boston lettuce which has different leaves than Bibb lettuce. It resembles a rose flower and has a sweet taste that can even be enhanced with the hydroponic ways of growth.

Still, you can choose from numerous varieties, since many of the lettuce types grow well with hydroponics. 

It’s only a matter of finding the right hydroponic system and providing the right growing conditions for hydroponic lettuce seedlings to transfer into beautiful leafy greens.

Best Hydroponic Lettuce Systems 

Lettuce is one of the veggies that thrive in water just fine, unlike carrots and potatoes that need vast spreading space and hydroponic systems that use less water. 

So, you can rely on a water culture hydroponic setup. These are the systems where the lettuce roots are submerged in water, and deep water culture is one of the best solutions.

In this type of hydroponic system, lettuce can thrive best with the roots being deeply submerged in water. Only the plant’s leaves appear above the water level, and the nutrient solution is included in the oxygenated water.

The lettuce, therefore, has everything it needs for proper development. Other than the small amount of growing medium used for lettuce seeds to germinate, there’s no special growing medium requirement for this method.

However, aside from the deep water culture method, you can grow hydroponic lettuce with other techniques as well.

Nutrient Film Technique Lettuce

One of the best ways of growing lettuce hydroponically is with the NFT system. It’s a controlled method and it can be considered a form of a flood and drain system. You can even buy a pre-assembled NFT system for leafy greens as they come with smaller containment zones.

Using this system for growing hydroponic lettuce is a good choice since the roots can’t spread too much to clog the channels. This is usually the biggest downside of NFT hydroponics, so you can rest easy knowing that your lettuce will grow just fine.

Here’s what you will need for this system:

• Growing channels with an inclined water outlet
• Water pump
• Nutrient reservoir
• Lettuce baskets or small containers
• Air pump
• Airstone

The system starts with a tank filled with nutrient solutions used for growing lettuce. The air pump is used to generate oxygenated bubbles by shooting onto the airstone, and this oxygenated mix is transferred to the growing channels.

Once the nutrient mix reaches the growth channels, it will burst through the lettuce roots, feeding the plant with fertilizer, and enticing growth. 

While growing lettuce hydroponically using this method, you can slightly incline the growth channels. 

Lettuce is a plant that thrives in water, and it won’t hurt the plant for the nutrient mix to stick around a while longer in the root zone.

How To Grow Hydroponic Lettuce With Ebb And Flow?

Another way you can grow lettuce hydroponically is with the Ebb and Flow system. It’s similar to NFT and uses a timer to switch the flood and drain cycles. 

Lettuce even might be the easiest vegetable to grow with this method.

You can feel free to set the timer to more than half an hour for the flood cycle, to let the lettuce thrive in the water. It will allow for larger amounts of water with the nutrient mix included to run through the roots of your veggies. 

Here’s what you will need for this system to work for growing hydroponic lettuce:

• Electric timer
• Growth tray
• Nutrient reservoir
• Water pump
• Growing medium

Some of the best growing mediums you can use for this method are hydroton, pea gravel, coco fiber, and stone wool. You don’t need an air pump or airstone with this method which can be a bit of a relief.

On the other hand, you’ll use the water pump to fill the growth tank with nutrient mixed water. This will submerge the roots directly under water mixed with fertilizer for proper growth. 

This hydroponic system is a slightly better option than NFT as in this case, you control the cycles and the lettuce enjoys deep water submersion. It’s a great way of forming your own hydroponic garden outdoors due to the space that it requires.

However, you can even set this system up indoors as it tolerates shade as well. Although, you will have to use grow lamps, in this case, to make up for the lack of sunlight.

The Kratky Method – Simple And Easy For Hydroponic Lettuce

This is one of the best ways of growing indoors hydroponic lettuce and is one of the most affordable ones as well. 

You don’t necessarily need any electric devices with the Kratky technique, here’s what is required for the system to work:

• Net pots
• A lid
• Growing medium 
• Growth tray
• Nutrient solution

In some cases, you might also need the grow lights as the only electric component of the system. 

However, if you have a window with sunlight access, you can easily grow one lettuce plant at a time with the Kratky method.

You will need a net pot to place the lettuce seedling in, and place a growing medium like coconut fiber inside. The pot should be placed above the nutrient tank with a lid that prevents full water contact.

Only the lettuce roots come in contact with the nutrient solution water. 

As time goes by, the water from the tank will be absorbed by the roots and an air gap will be created. It will provide enough oxygenation without the need for an air pump. The more water your lettuce absorbs, the higher the air gap will be.

Eventually, you just need to measure the nutrient levels and pH to ensure that your plants get the right treatment.

The Dutch Bucket System

One of the best hydroponic lettuce systems for circulating nutrient solutions is the Dutch Bucket system. 

It’s an often overlooked hydroponic technique that uses a regular aquarium pump to lead the water through the channel that spreads over a system of buckets.

It might not be the best hydroponic system for lettuce like DWC, but it still makes a convenient system that can easily be assembled. Here’s what you’ll need:

• Drip hose
• Water pump
• Lettuce buckets
• Growing medium
• Drain hose
• Nutrient solution

As mentioned, each bucket has an individual outlet where the water mixed with nutrient solution passes by. From this point on, it goes through the roots and exits through the drain hole.

The drain hose then collects the nutrient mix and leads the water back into the reservoir. The cycle repeats without the need for an electric timer. 

It’s best to place this system outdoors, so your lettuce plants can get their daily dose of sunlight for rapid advancement.

Why Is DWC Best For Hydroponic Lettuce?

Making a hydroponic lettuce garden is simplest with the deep water culture system. It’s simply due to the fact that the roots are constantly submerged in water filled with a nutrient solution mix.

Lettuce is a type of plant that actually thrives best in these conditions, and you can even expect the first harvest in six to eight weeks this way! 

DWC is also easy to set it up indoors, even though you might need some grow lights to compensate for sunlight.

Even with supplementary lighting, your lettuce will stay fresh. The DWC is also an appropriate hydroponic system for commercial lettuce growing. It easily substitutes the soil-based technique and even prevents soil-borne diseases and bacteria.

You just need to include a proper nutrient solution and it’s enough if you change the water with the nutrients every 10 days or so. 

The only things you’ll need for setting this system up even at home are a growth tray, nutrients, air stone, and air pump. There are no specific growing requirements and you only need minimum effort in changing the water every once in a while to get a 30% higher lettuce yield than with soil-based planting.

Creating Proper Conditions For Hydroponic Lettuce

Before even thinking about growing hydroponic lettuce, you should consider the optimal conditions that your hydroponic garden needs. These are not only associated with hydroponic nutrients, but also with other conditions that enable easier care and harvests.

Sunlight Access or Growing Lights

As you might know, lettuce is not a kind of plant that needs 6 or more sunny hours per day. It can be exposed to direct sunlight for a few hours, but it’s enough if you plant it indoors in partial shade with artificial light.

With up to 10 hours of partial light per day, your lettuce will thrive in hydroponic gardening. It also can benefit from a period of moderate night temperatures. 

Growing Mediums

Another crucial aspect is adding a growing medium into the net pots or growing baskets. 

With lettuce, you can settle on any form of growing medium, while some of them that can be especially successful include coconut coir, hydroton, and pea gravel.

You can even use rock wool for developing seedlings before you transplant them into a hydroponic system.

Nutrient Solution

As for the nutrient solution, you can use an NPK fertilizer with a higher Nitrogen ratio. You can also use Calcium nitrate and Epsom salts in the mix with the primary macronutrient solution.

With a solution like 5-10-20, you will get the lettuce plants thriving with a nutrient combination the contains a higher nitrogen ratio. 

By also adding Calcium nitrate to the mix, you provide a higher Nitrogen concentration in the mix.

Final Thoughts

Growing hydroponic lettuce is not as hard as it seems once you get yourself armed with the right tips. You can use the info from our guide to figure out the best hydroponic systems and growing conditions that could suit your garden.

Whether you use a DWC system that commercial growers use, or Ebb and Flow methods, you will get the highest yield with our information at your disposal. 

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