Aquaponics is a bio-mechanical system - a living eco-system that has to be balanced correctly for optimal bacterial, fish and plant biomass output, by using a mechanical system of pumps, valves, tanks, and grow beds designed and sized correctly to support the growth of the biological organisms. Since everything that lives in an eco-system is dependent on the other species for its survival, if one part of the system is not properly managed, it has a negative impact on everything else. In order to understand how to balance an Aquaponic ecosystem, you have to understand how the system operates at the biological and chemical level, so if something goes wrong, or you want to change the set-up, you will understand how to trouble shoot your system methodically.
This comprehensive work manual was written with the intent to provide the reader with the most important science-based concepts they will need to properly balance the growth of fish and plants in an Aquaponic ecosystem using a well design mechanical system.
After extensively reviewing the literature, speaking with countless number of professionals in the field of Aquaponics, and studying the economic models of most current Aquaponic operational businesses, I realized that there are many different ‘rules of thumb’ in the public forum that are in disagreement with one another, with some having merit and others being completely meaningless. For Aquaponic enthusiasts this can be a constant source of frustration. In this manual, I have attempted to simplify these various viewpoints, and provide only the ‘rules of thumb’ that have been shown scientifically to be reproducible. As a credentialed scientist, I have exercised my professional cynicism to separate the empirical & quantitative published research from my personal experience and/or bias and have instead attempted to only offer the reader an accurate reflection and review of the Aquaponic scientific literature and current state of thinking.
Dr. Rakocy has advocated using feeding rate ratios to balance Aquaponic systems for the last 20 years. Feeding rate ratios rules are defined as the amount of fish feed required on a daily basis to support a given plant growing area. Dr. Wilson Lennard and Sylvia Bernstein used Rakocy’s feeding rate ratios to offer a more simplified rule of thumb for balancing by relating the amount of fish biomass (not fish feed) required per square foot of growing area. However, both of these rules can be confusing to people who are not aware of the correct planting density for a particular plant species (defined mostly by the hydroponic industry). The reader needs to understand that all of these rules of thumb are approximations, and yield basically the same results. It should be noted that information and “rules of thumb” in practice based on scientific findings are not full-roof because ecosystems are inherently spatially variable, dynamic, and highly complex. More exact balancing can only occur "in-situ" with the actual system itself since all systems will work slightly differently depending on the fish and plant species being grown and the environmental conditions, even if the systems have the same design.
For commercial applications, there are far more exacting mathematical models for balancing the system for specific plant species and fish, various growing methods (continuous verses intermittent), and different media choices. Addressing all of these issues can be overwhelming to novice, so I have attempted to only provide general rules of thumb which are designed to be heavy on the fish load so that good plant growth is guaranteed. Once the reader understands the scientific principles behind these various rules of thumb, they can then have the confidence to trouble shoot their system more accurately for optimal plant and fish production.
Understanding the knowledge behind the science of Aquaponics will undoubtedly be beneficial, but in general running an Aquaponic system is simple in practice since it is a self-correcting living eco-system that is intrinsically robust. Even the most novice gardener can make many mistakes and still grow successfully and over time will gain the expertise to grow optimally. So just remember not to get intimidated, get your feet wet, and just have fun Aquaponicing!
For additional support please visit: www.AquaponicsFood4Thought.com or consult the references I provide at the end of the manual for more detailed information about this sustainable farming technology.
Rachel Tinker-Kulberg, Ph.D.
Copyright Statement © 2013 by AquaponicFood4Thought All Rights Reserved
Distributing, copying, or using portions of or excerpts from this material without the express written permission from the author is prohibited by law. Please use the material for your personal or educational use.
Table of Contents
Aquaponics is a Bio-mechanical Artificial Ecosystem 5
How to Properly Balance Fish & Plant Growth in an Aquaponic System 8
How to Schedule Fish stocking & harvesting to maintain a constant Fish Biomass 18
How to Schedule Plant Stocking & Harvesting to maintain a consistent Plant Biomass 24
How to Build and/or Size the Clarifying, Bio-filtration, Aeration and Water Circulation system 26
How to Cycle a new Aquaponic system to establish the Biofilter 47
How to maintain proper Water Quality Parameters in an Aquaponic system 49
How to Seed, Grow Transplants and Treat Plant Disease 75
How to obtain Organic and Gap Certification and ensure Food safety 77
Garden Layout, Production Management Schedule, & a Cost Benefit Analysis of a Small-scale
Aquaponic Production System 80
Aquaponic DVD (Work Manual)