Seeding For Aquaponics


Overview: How To Start Seeds

One of the best ways to ensure healthy plants in your aquaponics system is with healthy seedlings. This guide is going to break down your options and compare the pros and cons to each method. Depending on the size of your system will inform you which method is best for you!

The Soil Method To Start Seeds

Soil Is A great method for starting seeds, especially for those with experience gardening or traditional field agriculture.

Pros Of  Soil

Soil is cheap, readily available, and easy to work with. It provides reliable germination and is a good medium if the seed needs to be germinated in a warm medium. If you have a small to mid size system soil is a good option

Cons of Soil

Soil is subject to mold infestation and may contain a fungus or disease depending on the source. It is also very impractical for commercial growers who need hundreds to thousands of seedlings weekly. If you need more than 100 seedlings regularly we recommend one of the alternative methods.

How To Start Seedlings

Materials

  1. 72 cell plug tray  
  2. Bag of soil, look for low sand content
  3. Seeds
  4. Gloves
  5. Watering Can
  6. Lights and timer (indoor only)
  7. Beneficial Fungi Powder (optional)
  8. Oscillating fan
  9. Heat Mat (optional- for seeds that need 70F or higher soil temperature)

Procedure

  1. Place tray on table. Fill each individual cell with soil up to the brim. Gently press down to ensure soil isn’t loose. Top off if necessary. This 72 cell tray is adequate for the majority of plants. If you don’t need 72 cells just fill up as many as suits your systems requirements.
  2. Indent the soil in each cell with the tip of your finger(Photo). Indent should be a 1/2in deep or less for most seeds. Bigger seeds need deeper indents.Place 1 seed in each cell for larger seeds and 2-3 seeds in each cell for smaller seeds.
  3. (Optional) Sprinkle a little Beneficial Fungi Powder in each cell over the seed(s). We recommend using a spoon or a knife and gently tapping above each cell. If doing a large volume of seeds place powder in a small bowl and mix with seeds
  4. Sprinkle soil over your tray to cover the seedlings. You should not be able to see the seed with the naked eye.
  5. Water your tray until the soil is very Moist.

The Coir Method to Start Seeds

A very popular method for aquaponics gardeners to raise seedlings is to use a soil replacement. Recommend using coconut coir mixed with vermiculite in a even ratio.

Pros Of The Coir Method

Coir, especially organic coir, will not succumb to mold the way soil tends to nor does it have the issue of disease and fungi contamination like soil. In addition, if you see regularly you can reuse coir a few times which makes up for its high upfront cost. This is the best option for small to mid size system users.

Cons Of The Coir Method

Coir is practical to use for commercial growers but it has more labor and higher material cost than the biochar or expanded shale method. If you cannot access biochar or shale then coir will work for you. For small to midsize system users the only downside to the choir method is the slightly higher upfront cost.

How To Start Seedlings

Materials

  1. 72 cell plug tray  
  2. Bag of coconut choir 
  3. Bag of vermiculite 
  4. Plastic Tub 
  5. Seeds 
  6. Gloves 
  7. Watering Can (Photo, Amazon)

Procedure

  1. Mix bag of vermiculite and coconut coir together in the plastic tub. Mix with hands to break any clumps and to create an evenly distributed mixture. We recommend wearing gloves as the vermiculite can be hard to wash off.
  2. Place tray on table. Fill each individual cell with mix up to the brim. Gently press down to ensure mix isn’t loose. Top off if necessary. This 72 cell tray is adequate for the majority of plants. If you don’t need 72 cells just fill up as many as suits your systems requirements.
  3. Indent the mix in each cell with the tip of your finger(Photo). Indent should be a 1/2in deep or less for most seeds. Bigger seeds need deeper indents.Place 1 seed in each cell for larger seeds and 2-3 seeds in each cell for smaller seeds.
  4. (Optional) Sprinkle a little Beneficial Fungi Powder in each cell over the seed(s). We recommend using a spoon or a knife and gently tapping above each cell. If doing a large volume of seeds place powder in a small bowl and mix with seeds
  5. Sprinkle mix over your tray to cover the seedlings. You should not be able to see the seed with the naked eye.
  6.  Water your tray until mix is very Moist.
  7. Place tray outside in a well-lit area or inside directly under a light on 16 hours on, 8 hours off time setting
  8. If seedling requires mix to be above 70F place a heat mat beneath your tray(s).

The Biochar Method to Start Seeds

The Biochar method utilizes Biochar as the soil replacement for starting seeds. Biochar is a type of agricultural charcoal that is typically used as a soil additive to increase biological activity in soil, increase water and nutrient retention, and add more structure to the soil.

Pros Of The Biochar Method

Biochar is a renewable resource, it’s carbon negative meaning that it actually removes carbon from the atmosphere, its low cost to make at any volume and available for purchase as well. It is also reusable meaning you won’t need to constantly buy new soil medium. It is a very good choice for commercial and large scale home growers as you can start hundreds of seedlings in one tray.

Cons of Biochar

Biochar is not readily available through local suppliers, mainly online retailers. It is however pretty easy to make. In addition, it needs to be watered with aquaponics water. Not recommended for small systems.

Materials

  1. Plant Propogation Tray (Flat w/ holes)  
  2. 1 Gallon Biochar pellets 
  3. Seeds 
  4. Gloves (optional) 
  5. Watering Can 
  6. Lights and timer (indoor only)
  7. Beneficial Fungi Powder (optional)

Procedure

  1. Place tray on table. Fill tray with biochar pellets so that the tray is filled half the way up.
  2. (Optional) Mix seeds a beneficial fungi powder in bowl and coat all seeds.
  3. Sprinkle seeds throughout the tray. You should see a few seeds every square inch, but do not plant so densely you can’t see the biochar
  4. Run your hand over the top layer of biochar to jostle the seeds around.
  5. Sprinkle a layer of biochar over the top. We recommend taking the effort to crush it in your hands over the tray as the powdered biochar will cover the seeds better than full-size pellets. Both will work, however.
  6. Water with watering can until biochar is visibly moist.
  7. Place tray outside in the good sun or inside under a light connected to a timer.

The Expanded Shale Method to Start Seeds

The Expanded Shale method utilizes expanded shale as the soil replacement for starting seeds. Expanded shale is a type of gravel that is baked in a kiln until it “pops” like popcorn. This creates the expanded shale, after it pops, much like popcorn it becomes lightweight and also porous. This makes it a great medium for aquaponics increasing biological activity in the system

Pros Of The Shale Method

Expanded shale is relatively cheap compared to other mediums, especially at volume. It is very practical for large and commercial system growers as you can start hundreds of seedlings in a single propagation tray. Shale is also infinitely reusable.

Cons of Shale

Shale is not cheap until you buy it in bulk so it is not practical for small system growers. You also need to screen the shale so there is a bit of labor upfront but it is usable after the first time. Depending on the source your shale may be a fracking waste product. Source with caution.

Materials

  1. Plant Propogation Tray (Flat w/ holes)  
  2. 1 Gallon Expanded Shale, screened 
  3. Seeds 
  4. Gloves (optional) 
  5. Watering Can 
  6. Lights and timer (indoor only) 
  7. Beneficial Fungi Powder (optional)
  8. Oscillating fan (indoor only) 

Procedure

  1. Place tray on table. Fill tray with screened expanded shale so that the tray is filled half the way up.
  2. (Optional) Mix seeds a beneficial fungi powder in bowl and coat all seeds.
  3. Sprinkle seeds throughout the tray. You should see a few seeds every square inch, but do not plant so densely you can’t see the shale 
  4. Run your hand over the top layer of expanded shale to jostle the seeds around.
  5. Sprinkle a layer of shale over the top.
  6. Water with watering can until biochar is visibly moist.
  7. Place tray outside in good sun or inside under a light connected to a timer.

 

Caring for Your Seedlings

Water

Each day you will likely need to water. Until your seeds pop up, you want the medium to be moist but not damp to the touch. Once the seeds are popping up through the medium water once in the morning. In the evening check to see if the medium has dried out. If it is then water once more.

Light

If you are starting seeds outside, make sure you place them in an area that gets good sunlight. If you are starting seeds inside, you’ll need to place them directly under a light with a timer. You want the light about a foot away from the tray. Set the timer to run 16 hours on and 8 hours off. 

Air

If starting outside make sure seeds are in a well-lit area subject to breeze. If there is risk of temperatures falling below freezing bring seeds indoors for the evening. If starting seeds indoors it is highly recommended you set up an oscillating fan to provide a gentle breeze on your seedlings. The agitation will create a stronger healthier plant. We recommend 1-3 hours a day with the fan. If you don’t want to remember put the fan on a timer.

When To Transplant Into Your System

Identifying when to transplant a seedling into your system

Generally, it takes 2-4 weeks for seedlings to mature to the point where they are ready to transplant into your aquaponics system. You’re looking for the second set of true leaves. Most plants will sprout leaves in pairs. So you’ll see two leaves emerge, followed by another two leaves (this is the first set of true leaves) then you’ll see another two leaves emerge (this is the second set of true leaves). You can transplant anytime now. Depending on your system and timing you can let the seedlings grow out in the tray up to another two weeks but once the second set of true leaves emerges you should switch to watering with aquaponics water to ensure nutrients are available to your plants.

 

So there you have it. No matter which method you choose you are sure to get strong seedlings! Get out there and get growing.


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