How to grow marijuana in aquaponics

How to grow marijuana in aquaponics
In order to grow marijuana with aquaponics, you need to familiarize yourself with the basics of this system. The fish waste provides an organic nutrients for the growing marijuana while the plant roots filter the water. The nitrifying bacteria, that thrive in the growing media, convert the ammonia from the fish waste into nitrates that can be used by the cannabis plants.


I recommend you to use Flood and Drain system as it is very simple and effective.

Here are the key points of a flood and drain system:

  • The grow bed for growing marijuana is placed above the fish tank.
  • Water is pumped up from the fish tank into the grow bed.
  • When the siphon trips, water returns to the fish tank by gravity.

Simple aquaponic system for growing cannabis can be made of an Intermediate Bulk Container. You can use it  for making both fish tank and grow bed. 

Firstly you’ll need to remove the top bracket on the top of your IBC. You should flip this over and pull out the plastic so you can measure how deep you want the grow bed. Now that we have the plastic and the metal cage separated, the top of plastic container has to be cut off and then turned upside down in order to make a grow bed for the cannabis plants. To support that grow bed you can either make the outer rack or you can use the top bracket from your IBC attached to the metal cage.

Tubing and bell siphon

You should place a pump into the fish tank and assemble tubing. This tubing is used for pumping water up into the grow bed.

A bell siphon is used in flood and drain aquaponics systems in order to regulate the flow of water.  In this system water is pumped into the grow bed.  At a specific point (usually 2 inches below the surface) the water drains via the bell siphon.  When the water reaches the bottom you will hear the classic gurgle indicating the end of the drain phase.  The process will then repeat itself over and over again. 

What you’ll need to make tubing and bell siphon for growing marijuana in aquaponics:

Gravel Guard

  • 1 - 3" PVC pipe (approximately 12" long)

Bell Dome

  • 1 - 2" PVC pipe (approximately 10" long)
  • 1 - 2" PVC cap

Bell Siphon

  • 1 - 3/4" PVC pipe (approximately 6" long)
  • 1 - 3/4" to 1 1/2" bell adapter

Grow Bed Connections

  • 1 - 3/4" Male adapter (thread to slip)
  • 1 - 3/4" Female adapter (thread to slip)
  • 2 - #18 o-rings

Drain Pipe

  • 2 - 3/4" PVC pipe 4" long
  • 2 - 3/4" 90o elbow


  • Drill or Dremel
  • Drill bit (1/8")

Grow Bed for cannabis

Your marijuana plants need some water-resistant container they’ll grow in.  For this purpose you can use the top of IBC or build shallow wooden boxes (6 to 10 inches deep) and line them with pond liner.

You have to fill out the grow bed with an inert growing medium, such as expanded clay (light) or fine gravel (cheap, but heavy).  A mixture of expanded clay and gravel is a great choice for growing marijuana in aquaponics.

The Fish

To grow cannabis in aquaponics successfully you have to keep this ratio:  one pound of fish per gallon of water. Tilapia, catfish, koi and goldfish are the most common species used for aquaponics as well as other aquatic creatures like shrimp, crayfish or prawns. Tilapia and catfish adapt very well to aquaponics with marijuana due to their tolerance of less-than-perfect water conditions.

Cloning cannabis in aquaponics

Cloning is often used to take clones from female cannabis plant. In most cases for cloning you need a rooting gel and proper equipment. Somebody uses rockwool cubes or aerocloner for that purpose, however few people know that cloning cannabis in aquaponic system gives you a 100% outcome. All cuttings put out their roots in aquaponcs. All you need to do - is to cut out the cuttings, dig out holes in growbed and plant your clones. You don't need to spray your cuttings with water several times a day. No rooting gel or sophisticated cloning mashines are needed if you have aquaponic system for cannabis.

  Growing marijuana

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