How to Start Seeds in Your Aquaponics System

An aquaponics system can grow any plant you want to choose. However, to be successful, a grower's first step is to know the ideal growing conditions and the best varieties of plants suited to aquaponics systems. After gaining enough knowledge, the next step in starting an aquaponics system is to choose the right seeds to plant and plant those seeds properly. This article will discuss how to start seeds in your aquaponics garden and aims to provide you with all the knowledge you need to have a successful aquaponics garden.

To successfully start seeds for your aquaponics garden, you need to consider the following:

1. Laying The Proper Groundwork

Aquaponics is a symbiotic relationship between fish, plants, and bacteria. These three are the backbone of the entire system, and one cannot thrive without the other. Laying the proper groundwork means cycling your system and ensuring the fish are healthy and thriving to produce enough ammonia for the bacteria to convert into nutrients for the plants. Read our article, ”The Ultimate Aquaponics Beginner’s Guide” to learn more about aquaponics. 

2. Measuring The Bacterial Growth and Nutrient Level

After the cycling process, you should measure the bacterial growth level in the water to determine if it's the right level to start your aquaponics system properly. The three main things to consider here are:                                               

  1. Manage the ammonia levels adequately to ensure the water is safe for the fish.
  2. Ensure that the nitrites levels are within the ideal range.
  3. Measure and monitor the nitrates levels

You can measure the ammonia, nitrite, and nitrate levels by performing a water test and ensuring the water quality parameters for aquaponics are within their ideal range. 

3. Choose The Best Plants to Grow in Your System

Once your water quality parameters are within their ideal range, you can start planting your choice of vegetables and crops. To ensure the success of your system, choose plants that grow best in your climate and location


Seedling for Aquaponics Systems

4. Germinate and Plant Seeds Using The Correct Techniques

As mentioned above, it is essential to know the best plants to grow in your aquaponics system. But it is equally important to know the best methods for planting the seeds of your chosen plants. 

Seeds can be planted by direct sowing or germinating them in a seed starting trays and transferring them into the system once they're last enough to be transferred. Some plants can also be grown in an aquaponics system through their cuttings. 

What are The Best Seeds for Aquaponics Systems?

When it comes to growing aquaponics plants, the varieties are wide, and aquaponics growers can choose any plants as long as they know the growing conditions of these plants. The best seeds for aquaponics systems are lettuce, pepper, basil, tomatoes, and cucumbers. Below are the growing requirements for the seeds mentioned. 

Seed Germination Process

Germination is developing plants from seeds by giving seeds enough moisture. The seeds will go through imbibition, where enzymes are activated and start the process of growth. The seed's root will then develop, and shoots will begin to appear on the surface. The sprouts will then grow leaves and get energy from the sun to grow and thrive. Below are the most common reasons why seeds failed to germinate:

  • Over watering the soil or seed starting mix
  • Not good quality soil or seed starting mix
  • Seeds are exposed to too much light
  • Improper temperature for germinating seeds
  • Deeply planting the seeds
  • Poor seed quality

Materials Need for Germinating Seeds:

  1. Seeds
  2. Seed starter mix 
  3. Seed tray and humidity dome
  4. Seedling heat mat (optional)


Lettuce in Aquaponics


Lettuce is one of the most famous aquaponics plants because it is easy to grow in all aquaponics systems. It also grows fast and takes little monitoring. 

Things to consider in growing lettuce:

pH: 6.0 to 7.0
Temperature: 15°C to 22°C
Germination time: 7 to 14 days
Growing time: Most leafy lettuce grows in approximately 30 days. 

How to start lettuce seeds for your aquaponics system:

  1. Place 3 to 5 seeds in the starter medium, such as rock wool cubes, peat pellets, and plugs. You can also start your seeds in germination trays with heat mats
  2. Stick your growing medium into a growing tray, plate, or bowl. Water the growing tray and place your container in the dark.
  3. Mist the seeds or your growing medium once a day for up to 2 weeks.
  4. After 10 to 15 days, the seeds will sprout and are ready to transfer to your aquaponics grow bed, raft, or pipe.


Peppers in Aquaponics


Pepper is another popular plant for aquaponics because it is loaded with nutrients and gives flavor to most dishes. The varieties of peppers that can be planted in aquaponics are capsicum, piper, red pepper, and pimenta. 

Things to consider in growing pepper:

pH: 5.5 to 6.5
Temperature: 16°C to 24°C
Germination time: 7 to 10 days

How to start pepper seeds for your aquaponics system:

  1. Pre-mix your seed-starter mix with some water. Use a clean mixing bowl and gradually add water while mixing thoroughly.  
  2. Add the moistened seed starting mix to the containers, filling about ½" from the top. Use a medium to pressure the pack down the seed-starter mix.
  3. Using a pencil or pen, poke a small hole of about ⅛ deep in each that will be planted.
  4. Add 1-2 seeds per hole. Bury each seed with ¼" of growing medium.
  5. Ensure the seeds are well moistened by spraying a little water on the grow medium's surface.
  6. Place the planted seed trays on the seedling mat. If you're using a heat mat, set the temperature to 80°F (27°C). If you're not using a seedling heat mat, place the seeds in a warm location. 
  7. The seeds will germinate after 7 to 10 days.


Basil in Aquaponics


Basil is a herb rich in nutrients that helps maintain a healthy diet. Basil can be grown all year round and is great for indoor or outdoor aquaponics systems. 

Things to consider in growing basil:

pH: 5.5 to 6.5
Temperature: 18°C to 30°C
Germination time: 5 to 10 days

How to start basil seeds for your aquaponics system:

  1. Prepare your seed starting trays and fill them with seed starting medium.
  2. Sow 2-3 basil seeds per cell, planting them ¼" deep. Firm the seed, starting medium-well over the top.
  3. Keep the trays warm and moist until germination, which is about 5 to 10 days in ideal conditions. 
  4. Once the seedlings have at least one set of true leaves, you can start transferring them to your aquaponics systems. 


Tomatoes in Aquaponics Systems


Tomatoes are one of the best seeds for aquaponics systems because of their wide culinary applications. Tomatoes are easy to grow and mature fast once their nutrient requirements are met. To learn more about growing tomatoes in aquaponics, read our article, "How to Grow Tomatoes in Aquaponics.”

Things to consider in growing tomatoes:

pH: 5.5 to 6.5
Temperature: 23°C to 29°C
Germination time: 7 to 14 days

How to start tomato seeds for your aquaponics system:

  1. Decide on the tomato variety you want to grow.Prepare your containers for planting. Add the water to your potting mix to dampen it. Make sure the mixture stays compressed but not dripping wet. 
  2. Make a ¼ inch furrow in the potting mix, then sprinkle two or three seeds on the furrow and cover them with the potting mix. 
  3. Place the container in a warm area. Check daily to ensure the soil is always moist but not wet. Tomato seeds will germinate in about 7 to 14 days.


Cucumber in Aquaponics


Cucumber is a fruiting plant that is a common ingredient in salads but can also be eaten raw. Cucumbers have lots of health and are also one of the best seeds for aquaponics.

Things to consider in growing cucumber:
pH: 5.5 to 6.5
Temperature: 21°C
Germination time: 7 to 21 days

How to start cucumber seeds for your aquaponics system:

  1. You can directly sow your cucumber seeds in your system or germinate them on a seedling tray and transplant them later on. 
  2. To speed up the process of cucumber germination, soak the seeds before sowing overnight.
  3. Then fill a container with seed starter mix or organic potting soil mix. Gently press the mixture to remove air pockets.
  4. Poke small holes for each seed about a quarter-inch deep. Place one seed in each hole.
  5. Sprinkle additional mix to cover the holes with seeds about half-inch thick. 
  6. Sprinkle the seed starting mix with water to dampen. (Do not flood the container with water.)
  7. Place the container in a warm, full-light place of at least 70°f (21°C).
  8. Check daily to keep the planting mix moist until the seeds germinate in about 7 to 21 days. 

5. Maintain The Proper Conditions for a Successful High Yield

A successful aquaponics system requires regular monitoring and maintenance to ensure the proper conditions for growing fish, plants, and bacteria are met. To learn more about monitoring your system, read our article, "Maintenance Checklists for Aquaponics Systems.


Thank you for reading the article. Even though there are still some things to consider, starting your aquaponics seeds will turn out fine if you follow the correct steps and growing conditions. Feel free to leave your comment below. 


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