How do you Grow Lettuce in Aquaponics? Aquaponics Lettuce Production

Aquaponics Lettuce Production - How do you Grow Lettuce in Aquaponics?

Aquaponics is an alternative way to produce sustainable food anywhere and anytime. You can grow any plant through aquaponics, such as leafy vegetables and fruiting plants. How does aquaponics lettuce production work?

Aquaponics entails growing plants in the water alongside fish. The waste of fish is naturally transformed into nutrients by the bacteria present in the system. The nutrients ensure the lettuce has an ample supply of healthy food.

How does Aquaponics Lettuce Production Work?

You have an understanding of how vegetables grow in a traditional garden. You plant the seeds, water them, add a little fertilizer, remove invasive pests and weeds, and wait for the vegetables to grow,

In the aquaponics system, almost all of those processes happen automatically.

Aquaponics lettuce production works through the creation of a nitrogen cycle.

 Create a nitrogen cycle.
 Water is shared between grow beds and a fish tank.
 Fish produce waste in the fish tank.
 Wastes produced by the fish are high in ammonia.
 Pumps in the fish tank carry the waste to the grow beds.
 Bacteria in the fish tank transform waste into fertilizer with high nitrogen content.
 The lettuce plant extracts nitrogen from the water.
The water again becomes safe to be reintroduced to the fish tank.

The nitrogen cycle continues to repeat its process through this simple process:

 The fish provides nutrition to the bacteria.
 The bacteria provide nutrition to the lettuce plants.
 The lettuce plants function as a biofilter for the fish.

All you need to do to grow lettuce in the aquaponics system is to feed the fish.

Traditional Planting vs. Aquaponics

You can treat aquaponics planting in the same way as when planting in a typical garden bed.

There are, however, some things that separate both planting systems:

 Aquaponics planting produces a high yield because it can be done year-round.
 Aquaponics does not need a vast planting area. You can set up an aquaponics system anywhere in your home or a small yard
 Aquaponics only requires a small amount of water. It only requires about 10% of the water needed for the same plant to grow when planted on land.
 Aquaponics planting uses fish waste as fertilizer.

The aquaponics system allows you to grow lettuce at home for your own consumption. This vegetable is a popular choice to grow in aquaponics because it does not need complicated nutrients and is easy to maintain.

Benefits of Aquaponics

Many residents who do not have much space in their homes for a vegetable garden turn to aquaponics to grow their own food.  Aquaponics also comes with other benefits.

•  Growing Organic and Healthy Produce. The aquaponics system does not use herbicides, hormones, or pesticides for plant growth.
•  Faster Plant Growth. Plants in an aquaponics system have access to nutrients from fish wastes 24 hours a day; thus, they grow faster. While it takes the lettuce plant two months to grow in soil, it only takes the plant one month to grow in an aquaponics system.
 Growing vegetables in an aquaponics system mean you always have access to fresh produce in your home.
 An aquaponics system uses techniques that guarantee continual reuse.
•  Low in Maintenance. You do not have to water your plants with the aquaponics system, do weeding, and contend with pests infiltrating your plants.

It is not too expensive to install an aquaponics system in your home. A basic aquaponics system costs just a few hundred dollars.

Growing Lettuce in an Aquaponics System

Lettuce is easy to grow in an aquaponics system. However, to be successful in aquaponics lettuce production, you will need to provide the best conditions.

Water and Air

The best water temperature for lettuce to thrive is between 70 °F and 74°F. This is also a suitable water temperature for many fish to thrive. This makes aquaponics lettuce production ideal.

Good airflow is also essential to increase transpiration (photosynthesis) and nutrient consumption.

pH Level

Your lettuce plant will thrive at a pH level of between 5.8 and 6.2. This plant can also survive beyond this pH range. Water with a higher calcium level prevents leaves from burning on the tips during summer.

Be careful because your lettuce will not taste as good or will not be as large when pH levels are not within the ideal range.

Spaces between Plants

Plant lettuce 7 inches apart. This will promote maximum growth of the plant because it will:

 Prevent blocking of the light.
 Overcrowding of the plants.
 Prevent the plants from “fighting” over available nutrients.

Beneficial Insects or Predator Bugs

The aquaponics system is less prone to pestilence than traditional gardens because there is no soil and this system is easier to maintain; it does not, however, mean that there will be no pests.

Pesticides can harm the pests, yet, they are harmful to the fish and you. Beneficial insects and predator bugs can replace pesticides. These insects will eat the pests but will not eat your lettuce.

Methods for Aquaponics Lettuce Production

There are many methods you can use to grow lettuce in an aquaponics system. Grow beds and the deep-water culture or floating raft are the most common methods.

Choosing the correct aquaponics system method will allow you to harvest good and healthy lettuce within 4-5 weeks. It will also give you the highest yields.

Deep-Water Culture

This method uses rafts made of materials that float easily on water, such as foam sponges or Rockwool. There should also be a permanent water supply.

Lettuce seeds are “planted” in individual holes in the raft. The plant’s roots hang in oxygenated water pumped through the growing portion of the fish tank and back to the growing area of the lettuce. This allows the roots to take in all the nutrients they may need to grow quickly, strong, and healthy.

Once you have “planted” the seedlings all that is needed to be done is to schedule a transplant for proper spacing. There is nothing you need to do then but wait for harvest time.


Create a grow bed (seed starter cubes) with Rockwool.  Plant the lettuce seedlings. Roots of the lettuce plants will not always sit in the water when in grow beds. Instead, bell siphons handle the drain cycle.

The drain cycle will allow the lettuce plants to access the nutrients, oxygen, and water they need in the same manner as the raft system.

How do you Grow Lettuce in Aquaponics?

Lettuce is the most popular and the best crop to grow through the aquaponics system. Planting a mixed variety of lettuce in your aquaponics system will give you a steady supply of fresh lettuce.

Mixed varieties of lettuce in your aquaponics will mature and be ready for harvest at different times. You will also have lettuce in different flavors and crispness. You can choose from any of these categories:


Here is the aquaponics lettuce production process using the raft system.

What you need:

 Styrofoam sheets (one-inch thick)
 Any container that can fit at least 10 gallons of water. You can also use an aquarium.
•  Pump and under gravel filter. You will need a pump to pull the water across the gravel for biofiltration.
•  Growing Medium. Rockwool cubes where you will “plant” the lettuce seedlings.
•  Aquarium Gravel. This is used to prevent the leaching of the water to maintain its pH level.
•  Light Source. While aquaponics is best placed close to a sunny window, it will need artificial lights for at least 16 hours a day to better plant growth.
•  Siphon Cleaner. Needed for monthly maintenance of the tan.
•  pH Test Kit. Needed to ensure the pH level of the water is maintained.

What you need to do:

Growth time: 4-5 weeks.

Plant width: 25 to 35 centimeters

Plant height: 20 to 20 centimeters

1. Plant lettuce seeds 18 to 30 centimeters apart.

2. Maintain a water temperature of 70 °F and 74°F.

3. Maintain a water pH level of between 5.8 and 6.2.

4. Introduce a phosphorus supplement after two weeks to prepare the plants for transplanting,

5. Transplant the lettuce plants after three weeks (when the plants have 2 or 3 leaves).

6. Ensure to have a high nitrate level at all times to ensure sweet and crisp lettuce.

7. The best fish match for lettuce:


8. Maintenance

 Check pH level weekly. Adjust pH level with a pH Up and Down liquid solution if it reaches above 7.
 Always use de-chlorinated water in the tank.
 Use a siphon cleaner to vacuum excess fish waste out of the tank.

9. Harvest your lettuce after 28 days or when the leaves and heads are large enough. An early morning harvest is always the best time when the lettuce leaves are moist and crisp.

Final Thoughts

Aquaponics is a planting system that is easy to create and maintain. Aquaponics lettuce production is best for beginners. You will enjoy building your rafts and watching your lettuce grow.

Not having enough space in your yard or not having a yard is not a deterrent to growing your own lettuce.

Follow the guidelines outlined above to ensure the success of your aquaponics lettuce production.

 Jenny M
Tribal Writer

Edited by
Patricia Godwin

Patricia Godwin

Patricia has many years of experience as a content writer on various subjects, but her first love is gardening. She’s never met a plant she didn’t like and, consequently, she writes about every type of plant you can think of. Once an avid gardener with a herb garden, a succulent rockery, and a rose garden – to mention a few. Nowadays, she’s constantly on the move searching for interesting plants to bring to your attention; and explain to you all the details you need to grow, care and maintain these plants.

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