How Long Does Lettuce Take To Grow In Hydroponics

by RightFit Gardens | Last Updated: June 4, 2021

The process of growing your vegetables is rewarding and a job that you must do with the utmost care and responsibility. Moreover, homegrown vegetables taste better than those that you buy. Lettuce is one of the many house garden plants. Growing lettuce hydroponically is a hobby that is even more self-satisfying than growing lettuce conventionally. Growing hydroponic lettuce may appear to be a time-consuming and complex process; however, it’s a lot of fun if you know what you’re doing.

In case you have forgotten, hydroponic gardening consists of growing plants without the aid of soil, only using the nutrient solution and moist air. Thus, you could grow lettuce hydroponically. We’re here to help you, so don’t be afraid if it seems like a daunting task.

The easiest plant to grow hydroponically is lettuce. Especially for beginners, it would be advisable to start with lettuce as lettuce is an easy plant to grow and care for and produce healthy results. How does hydroponic lettuce grow?

A Guide To Hydroponically Growing Lettuce

lettuce-hydroponicThere are only a few varieties of lettuce plants to choose from. We have Bibb lettuce, Tom Thumb lettuce, and Romaine lettuce. But how are they different? The easiest lettuce type to grow is Bibb lettuce. If you’re seeking a small space consumption, Tom Thumb is a better option. Romaine lettuce is also as tasty as others, but it takes a long time to grow.

Once you choose the type of lettuce you want to grow, you need to choose the hydroponic system you want to use.

Numerous systems exist, such as ebb-flow systems, drip systems, aeroponic systems, and Nutrient Film Technique systems. Deep water culture is best for growing lettuce, however. Plants grow in this system by floating on top of the water level, and their roots grow into the water, taking in all the nutrients they need.

To hydroponically grow lettuce, you need to pick a suitable medium. Several mediums can be used, such as coco fiber, pine shavings, sand, rockwool, vermiculite, and river rock. You can choose the one that is most suitable for you since they all have high success rates.

Despite this, rock wool is the most preferred material due to its porous nature and its sterility. You must, however, be cautious not to overwater the roots since excessive water can cause rot and suffocation.

Grow rock is another popular option. If you’re producing on a small scale, you can clean and reuse it; however, it can be exhausting if it’s on a larger scale.

Installing your water reservoir is the first step in setting up your system. You will store water and nutrients in this reservoir for use by your plants.

The size and surface area of the container that will serve as your nutrient reservoir can be whatever you prefer, but make sure it is at least 8 inches deep. The roots must be able to immerse themselves in the water entirely, or else everything will fail.

When choosing a container, it is recommended to avoid all metal options. When a metal container oxidizes or rusts, it will cause stress on your plants, causing their nutrients to be disrupted.

Putting the plant in a net pot is the only way to grow a hydroponic plant. The roots will float on a surface above the water in this net pot, so the water will not contact the roots. Take advantage of all the net pots you can.

Make holes in a polystyrene plank. These holes are required to accommodate the net pots over which you will place the plants. There should be at least 12 inches between each hole so for excellent plant growth.

Fill in as many holes as possible so that you can fit in as many net pots as possible.

Lettuce, in particular, requires an air pump to keep the water in the reservoir fresh.

Ensure that the reservoir is fitted with a high-quality air pump. Using this pump will ensure the circulated water contains oxygen dissolved in it. It will also ensure freshwater is being circulated to prevent suffocation.

The reservoir finally needs to be built. Then add the right amount of water, followed by the hydroponic nutrients. This type of nutrient is usually sold already mixed for convenience.

Plants differ in their needs for nutrients, so the nutrients that you mix will depend on them. In addition to magnesium and potassium, lettuce needs calcium as well. It would help if you also kept in mind that the nutrients will vary depending on the lettuce variety you grow.

Some lettuce varieties may be sensitive to nitrogen, so make sure you look into it.

A hydroponic garden cannot be grown directly in the setup. Initially, seeds should be grown in a small nursery, which provides the right environment to become stable. You can use egg cartons or plugs for this purpose, and you can fill them up with your chosen media before you begin to germinate your hydroponic seeds.

Setting Up a Hydroponic Lettuce Garden

To get the lettuce seeds going in your small nursery, you need to take care of the seeds in ideal conditions properly. They should be watered regularly and placed in a place with good circulation that is well-lit.

Temperatures between 65 F and 80 F would be ideal. Be sure to take good care of the lettuce seedlings until they reach a height of 2 inches and develop four leaves.

Place your net pots into the holes drilled in the polystyrene plank. It would be best if you placed the plants into their net pots as gently as possible after removing them from the nursery.

Fluorescent lighting is ideal for head lettuces. Each day, ensure that the lettuce crops receive 10 to 14 hours of light. Healthy lettuce usually does not require much natural light compared to other plants. The best type of grow light to use is fluorescent light because it is affordable, especially if you are a beginner. Additionally, it uses low power and produces little heat, so it’s great for your plants.

Maintaining the right temperature for your lettuce is crucial. Cooler temperatures suit them well rather than warm climates. It would help if you kept temperatures between 55 and 75 degrees Fahrenheit at night and 75 degrees Fahrenheit during the daytime. Overheated lettuce will flower or bolt, resulting in a bitter taste.

For a plant to get the maximum amount of nutrients, it is vital to keep the pH level in check. A pH of 5.5 to 6.5 is optimal for most cases. Make sure that it is acidic by checking its pH level regularly. Reservoir pH adjusters can assist with leveling the pH. Ideally, you should purchase both pH down and pH up adjusters.

How To Maintain Your Hydroponic System

Hydroponic plants require a lot of air circulation. When air surrounding them is not properly circulated, mildew and bacteria tend to grow due to their high moisture requirements.

Plants can suffer as a result. You can circulate air better by installing exhaust fans, floor fans, ceiling fans, or even by keeping a window open. However, whatever you do, ensure that there is enough ventilation.

Algae often grow in damp conditions. Under direct sunlight, hydroponic setups can easily support algae growth, so you should be very careful when using them. To avoid such a situation, place a shade over your plants.

You must keep all insects away. Mesh the windows and vents if there are any. Suppose there are any flying insects in the area; set up fly traps.

Look out for water-induced mildew. If you thoroughly clean and sterilize all your equipment that comes into contact with water, you can avoid this problem. Any 2% bleach solution will do the trick.

To fully grow a head of lettuce takes between five and six weeks. Then you can pick its leaves for consumption. Nevertheless, fresh lettuce leaves regenerate themselves quickly. To promote growth, it is best only to pick the outer leaves.

Mix it up. A plant can only produce so many leaves at a time. To maintain a stable production rate, ensure that all leaves are picked somewhat.

Although the plant is fully grown, you should not pick it at this stage. Nevertheless, you must preserve the freshness for later use. By moving the plants to cooler places, you will be able to preserve their freshness for up to one month. A near-freezing temperature is ideal.


By the time you’ve read this, you’ll be able to determine for yourself that hydroponic lettuce is easy to grow and requires little effort. Trust us; you will be more than satisfied with the final product.