Understanding Aquaponics: A Symbiotic Relationship

The concept of aquaponics has been around for quite some time, fish living in a symbiotic relationship with food plants.  The fish produce waste that the plants feed off of to get their nutrients; in return, the plants detoxify and clean the water in the process. 

Challenges in Aquaponics: Phosphorus and Iron

While the theory is mostly sound there are some obstacles that must be overcome to really maximize the efficiency.  The two nutrients that are going to limit growth the most are phosphorus and iron as these naturally have poor solubility. 

Cannabis plants require many different nutrients to thrive. Growing cannabis in aquaponics presents some difficulties 

Algae water

Algae Blooms: A Potential Problem

The dilemma here is that these nutrients are also a limiting factoring in algae growth so adding them to the water could trigger an algae bloom. Some species of algae are also toxic to fish.  Additionally the algae can't be controlled with Hydrogen Peroxide like you may do in hydroponics because it is toxic to fish. 

Grower spraying Foliar Spray on plants

Foliar Feeding: A Solution for Nutrient Supply

In order to keep a constant supply of nutrients a foliar feed should be considered.  Refer to our previous blog post, How to Use Foliar Spray for details on how to properly apply.  Keep in mind not to add too much or can drip off and contaminate the water.  Apply regularly, at least every other day.

A plant's roots are submerged in a glass of water where a fish is swimming

Feeding Rates in Aquaponics

The feeding rates might be a little tricky.  A well established system is going to be generating its own nutrients, which is the whole point of aquaponics.  These are very general directions and should be adjusted by the user, since there will be so many factors, no two systems will be the exactly the same.  For example Tilapia and Trout eat very different things so the nutrition of their rations will differ and how they metabolize it will also differ.   


All of the following dosages are in milliliters per liter. 

Future Harvest 3 part Holland Secret container

Early Vegetative

1 ml Holland Secret Grow

2 ml Holland Secret Micro

1 ml Holland Secret Bloom


Future Harvest 3 part Holland Secret and Calnesium bottles side by side.

Late Vegetative

3 ml Holland Secret Grow

2 ml Holland Secret Micro

1 ml Holland Secret Bloom

1 ml Calnesium


Future Harvest nutrient bottles for the late vegetative feed stand side by side


Flowering and Fruiting

2 ml Holland Secret Micro

3 ml Holland Secret Bloom

2 ml Flowering Additive (Bud Start for early, Ton-O-Bud for middle, and Bud Boom for late)

1 ml Calnesium

These directions should provide a lifeline to give your plants their basic nutrition, but don't expect yields comparable to a hydroponic growing system which puts plant nutrition first.  If the focus is on raising fish, then this loss in yield shouldn't be a concern.  

Three gold fish in a bowl gather around the roots of a submerged plant.

Managing Deficiencies and Over Fertilization

As previously stated, the biggest problems faced will be deficiencies with phosphorus and iron so be sure to familiarize yourself on what these problems look like in your species of plant.  Also watch for signs of over fertilization like leaf curl and cut back if necessary, although this seems to be less of a concern. Should an algae bloom occur be aware that some algaecides contain herbicides and can kill plants so be sure to read the label thoroughly before using.  



Any questions? Email us at marketing@futureharvest.com or send us a message on Instagram @futureharvestdevelopment 

Happy growing!