Glenn Martinez and Staff – Olomana Gardens
Dr. Clyde Tamaru – Hawaii Dept of Agriculture, January 15, 2011
Dr. Kai Fox – Hawaii Dept of Agriculture, January 15, 2011
Hawai State Hospital, January 22, 2011
Stan – Waimanalo Feed Supply, March 2, 2011
Lessons for Pre-School Students
Where does our food come from? From the ground or from stores? What is quality food? What kinds of food should we eat? What is organic food? How can we eat healthy food? How can we grow food in our back yard?
Lessons for High School Students
Definition of Aquaponics
Aquaponics is a sustainable food production system that combines a traditional aquaculture (raising aquatic animals such as fish, crayfish orprawns in tanks) with hydroponics (cultivating plants in water) in a a symbiotic environment. In the aquaculture, effluents accumulate in the water, increasing toxicity for the fish. This water is led to a hydroponic system where the by-products from the aquaculture are filtered out by the plants as vital nutrients, after which the cleansed water is recirculated back to the animals. The term aquaponics is a portmanteau of the terms aquaculture and hydroponic.
Freshwater fish are the most common aquatic animal raised using aquaponics, although saltwater fish, crayfish and prawns may also be used. In practice, tilapia are the most popular fish chosen for home and commercial projects that are intended to raise edible fish, however barramundi and Murray cod are also used. Most green leaf vegetables grow well in the hydroponic filter, although most profitable are varieties of chinese cabbage, lettuce, basil, roses, tomatoes, okra, cantaloupe and bell peppers. Other species of vegetables that grow well in an aquaponic system include beans, peas, kohlrabi, watercress, taro, radishes, strawberries,melons, onions, turnips, parsnips, and herbs. Since plants at different growth stages require different amounts of minerals and nutrients, plant harvesting is staggered with seedings growing at the same time as mature plants. This ensures stable nutrient content in the water because of continuous symbiotic cleansing of toxins from the water that in high levels kill fish.
Aquaponic systems do not typically discharge or exchange water under normal operation, but instead recirculate and reuse water very effectively. The system relies on the relationship between the animals and the plants to maintain a stable aquatic environment that experience a minimal of fluctuation in ambient nutrient and oxygen levels. Water is only added to replace water loss from absorption and transpiration by plants, evaporation into the air from surface water, overflow from the system from rainfall, and removal of biomass such as settled solid wastes from the system. As a result, aquaponics uses approximately 2% of the water that a conventionally irrigated farm requires for the same vegetable production.This allows for aquaponic production of both crops and fish in areas where water or fertile land is scarce. Aquaponic systems can also be used to replicate controlled wetland conditions that are useful for water treatment by reclaiming potable water from typical household sewage. The nutrient-filled overflow water can be accumulated in catchment tank, and reused to accelerate growth of crops grown in soil, or it may be pumped back into the aquaponic system to compensate for the water lost in periods of drought or little rainfall.
The three main inputs to the system are water, feed given to the aquatic animals, and electricity to pump water between the aquaculture and the hydroponics. The hydroponics system continually provides plants such as vegetables, while the aquaculture can contain edible species of among others fish, but they will have to be replaced to keep the system stable.
Definition of Permaculture:
Permaculture is an approach to designing human settlements and agricultural systems that are modeled on the relationships found in natural ecologies.
Permaculture is sustainable land use design. This is based on ecological and biological principles, often using patterns that occur in nature to maximise effect and minimise work. Permaculture aims to create stable, productive systems that provide for human needs, harmoniously integrating the land with its inhabitants. The ecological processes of plants, animals, their nutrient cycles, climatic factors and weather cycles are all part of the picture. Inhabitants’ needs are provided for using proven technologies for food, energy, shelter and infrastructure. Elements in a system are viewed in relationship to other elements, where the outputs of one element become the inputs of another. Within a Permaculture system, work is minimised, “wastes” become resources, productivity and yields increase, and environments are restored. Permaculture principles can be applied to any environment, at any scale from dense urban settlements to individual homes, from farms to entire regions.
OBREDIM design methodology
OBREDIM is an acronymfor observation, boundaries, resources, evaluation, design, implementation and maintenance.
- Observation allows you first to see how the site functions within itself, to gain an understanding of its initial relationships. Some recommend a year-long observation of a site before anything is planted. During this period all factors, such as lay of the land, natural flora and so forth, can be brought into the design. A year allows the site to be observed through all seasons, although it must be realized that, particularly in temperate climates, there can be substantial variations between years.
- Boundaries refer to physical ones as well as to those neighbors might place, for example.
- Resources include the people involved, funding, as well as what can be grown or produced in the future.
- Evaluation of the first three will then allow one to prepare for the next three. This is a careful phase of taking stock of what is at hand to work with.
- Design is a creative and intensive process, and must stretch the ability to see possible future synergetic relationships.
- Implementation is literally the ground-breaking part of the process when digging and shaping of the site occurs.
- Maintenance is then required to keep the site at a healthy optimum, making minor adjustments as necessary. Good design will preclude the need for any major adjustments.
Holmgren’s 12 design principles
These restatements of the principles of permaculture appear in Holmgren’s Permaculture: Principles and Pathways Beyond Sustainability also see permacultureprinciples.com;
- Observe and interact – By taking time to engage with nature we can design solutions that suit our particular situation.
- Catch and store energy – By developing systems that collect resources at peak abundance, we can use them in times of need.
- Obtain a yield – Ensure that you are getting truly useful rewards as part of the work that you are doing.
- Apply self-regulation and accept feedback – We need to discourage inappropriate activity to ensure that systems can continue to function well.
- Use and value renewable resources and services – Make the best use of nature’s abundance to reduce our consumptive behaviour and dependence on non-renewable resources.
- Produce no waste – By valuing and making use of all the resources that are available to us, nothing goes to waste.
- Design from patterns to details – By stepping back, we can observe patterns in nature and society. These can form the backbone of our designs, with the details filled in as we go.
- Integrate rather than segregate – By putting the right things in the right place, relationships develop between those things and they work together to support each other.
- Use small and slow solutions – Small and slow systems are easier to maintain than big ones, making better use of local resources and producing more sustainable outcomes.
- Use and value diversity – Diversity reduces vulnerability to a variety of threats and takes advantage of the unique nature of the environment in which it resides.
- Use edges and value the marginal – The interface between things is where the most interesting events take place. These are often the most valuable, diverse and productive elements in the system.
- Creatively use and respond to change – We can have a positive impact on inevitable change by carefully observing, and then intervening at the right time.
Building an aquaponics system is one of the wisest and most important decisions you will ever make. With the state of the economy today, it is good to know that with your aquaponics system you are now in the food business – for yourself. Imagine all the fresh organic produce and great tasting fresh fish you love to eat and now have plenty of; plenty to share with family, friends and neighbors.
Everything seems connected to non-renewable fossil fuels now, and price of oil is out of control. Food prices as well, and with it, my peace of mind and sense of self‐empowerment. aquaponics may be the tool to help us get back on track, since gardening is not everyone’s thing. Bending over, dirty hands, weeding, pest control, soil repair and regeneration, etc. With your own aquaponics system you will be:
Has low set‐up and operating expenses
Grows most food groups
You have the choice of simply going off‐grid
Assembly is easy and straight‐forward from materials, the majority of which you can buy off the shelf
Operation is simple (you feed the fish, propagate the seeds and harvest the plants).
Living independent of escalating food and transportation costs
Off the shelf products.
Easy assembly doesn’t require specialized labor.
Plenty of options to use recycled materials.
The money you save by growing your own organic produce – the system will pay for itself in under a year.
Your aquaponics system is scalable. If you too love this and it works well for you, you may choose to upgrade to a 3 plant bed system, a full family system or even a commercial one.
You produce both fish and organic fruits and vegetables in symbiosis with one another, because the fish provide an exceptional amount of bio‐available nutrients and the vegetables clean up the water for the fish! Don’t even think about using pesticides on your veggies – not that you’ll need to, since you are off the ground without weeds, soil pests or pathogens.
Your produce tastes so much better than those grown in the ground and your fish will thrive better and easier than in any stand‐alone aquaculture system. Additionally, you save yourself 95% of the water it would take to grow the same amount of veggies in the ground, and your greens will thrive in half the time or less, much more densely planted. When you add this up you will find that you produce 8 to 10 times the amount of organic produce that the same area of ground would have produced in the same amount of time. No more bending over, either – the plants are grown at waist‐level and can be harvested with ease. It’s farming on‐the‐go. You will use a small amount of energy, which you may choose to harvest off‐grid with a clever photovoltaic, wind or hydroelectric set‐up. Or tying into the grid will only use about $20 per month at peak US rates.
Points to Consider
The system that we are introducing is almost as simple as one can get. The entire aquaponics protocol has many different variables to consider:
Where in the world do you live? How cold does it get in winter? Which plants/greens love your climate? What are your local fish options? Where on your property will you locate your new aquaponics system?
You will need sun or an alternate heat and light source to keep the water at optimal temperature for the fish. Consider placing your system in your garage or a small greenhouse for protection if you live in the hot desert or in perpetual winter. The aquaponics system is small enough and compact enough that it requires as little as 30 sq ft.
What greens and/or vegetables do you like? Think types of lettuces, dark leafy greens, tomatoes, cucumbers, culinary herbs, cabbages, oriental stir fry varieties, silver beets, kohlrabi, green onions, chives, leeks, etc… With a green‐ or screen‐ house or in your garage with good full spectrum lighting, fruiting plants such as melons, cucumbers, squashes, tomatoes, strawberries, peppers, okra, and legumes such as peas, sugar snap peas, purple beans, green beans and others might do very well.
Check out sites such as http://www.seedsofchange.com or http://www.horizonherbs.com for organic seed options. By the way, using the water from the system to irrigate ground‐based plants has shown tremendous benefits to those plants as well. Sweet potatoes, carrots, onions, asparagus, bush crops, and so on, all love the nutrient‐rich aquaponics water.
And of course the fish! Contact your local University or Ag extension office to find out which fish are legal to grow in your state or country. Some species that may work well are: Tilapia, Chinese Catfish, Koi, Bluegill, Crappie, Largemouth and Smallmouth Bass to name a few.
Keep a number of the appropriate fish in a simple container filled with their favorite stuff: water.
Care for the fish
Aerate the water for optimal dissolved oxygen levels (DO) and provide yummy fish food twice a day, which can be automated, and make sure they don’t get too cold. On a weekly basis, check the water pH level to make sure that it remains at optimal levels. Through a two‐step process, nitrifying bacteria will turn the fish excrement from toxic ammonia into valuable nitrates, providing the fundamental growing nutrients for your favorite plants.
Propagate seeds in netted pots. The roots will reach into the water, extracting the nutrients and effectively cleaning the water for the fish.
Pump the water flow from the fishpond on the ground up to table level height where the veggie container(s) are and gravity will deliver the filtered water back to your fish nice and clean.
There are really only 3 chemistry/ physics concepts to understand. Get yourself a test kit to play with, which is the easiest way to learn about what’s happening in the tanks at all times. In the beginning, as you are optimizing your system, you will need to test more frequently, but within a few weeks you will end up testing less and less as you fully understand the relevant causalities. Do test! Find a way to look at testing the physical parameters as play, exploration, life and death – whatever keeps you at it until it clicks!
Happy fish = high plant yield
Dead fish = no plant yield
Dissolved oxygen (DO)
The fish need this to breathe and you either provide it with a small air pump connected to multiple ‘air stones’ deep in the fishpond alone, or you supplement a smaller pump with our special energy‐saving solution as detailed in the construction portion of this manual. Aeration is critical to the survival of the fish, so you may want to consider back‐up scenarios during potential power outages!
Ammonia/ Nitrites/ Nitrates
Fish poop and urine contain ammonia, which is toxic to the fish and vegetables. The answer to this otherwise deadly problem is provided by nature herself: nitrifying bacteria that turn ammonium first into nitrites and then into nitrates. So before you can grow vegetables with the water from the fish tank you need to have nitrates. It may take as long as 3 months for the nitrates to show up on their own naturally, so if you are in a hurry you may choose to inoculate your system and get the process going as early as one week.
Calcium carbonate/ potassium carbonate/ iron chelae. When needed, the carbonates provide extra potassium and calcium to the plants and raise the pH as well. If your plants seem a little yellow, they are probably iron deficient; add iron chelae directly into the grow bed and this will take care of the problem.
As you begin testing the water on a regular basis – more so during the startup phase – there are certain targets for each of the particular chemistries.
DO – 80% saturation is the goal, as this allows for maximum nitrification rates. Empirically, this translates to not less than 4ppm.
The temperature for optimum growth of nitrifying bacteria is between 77‐86° F (25‐30° C). Anything in this range is ideal. Most of the fish you will select can comfortably tolerate cooler waters, and the plants themselves would prefer the lower end of this target.
This is an interesting target to work out, as there are at least three different variables at play here: fish, plants, and nitrifying bacteria. All things being considered, you want to be slightly basic with your water solution. A general high and low range, which should not be exceeded, is between 6.0 and 8.0. Plants prefer lower pH, and the fish prefer a higher pH, so it’s best to try to aim for happy medium of 7.0 If the pH gets too low, you can always add Calcium Carbonate (crushed coral) or either Phosphoric Acid, di‐sodium phosphate, or mono‐sodium phosphate.
Ammonia levels should not be allowed to exceed 6 ppm, which is already considered toxic. The goal is zero detectable ammonia or ammonium (the ionized version of ammonia). But of course therein lies the trick…zero detectable, but not zero, so in reality less than 1ppm is good. If there’s no ammonia, there’s no food for nitrosomonas, which means no food for nitrobacter, which means no food for the plants. Somehow, it all works out.
Add the total fish population part by part to the goal of about15 fish. In this way, the nitrifying bacteria will have a chance to “catch‐up” to the increases in ammonia.
Nitrates and Nitrites
As with Ammonia, nitrites are toxic to the fish in particular. Nitrates are necessary for plant growth. With nitrites, you do not want to exceed 6ppm, which again is already considered toxic. Keep nitrite levels at or below 1ppm. As for nitrates, which are more easily tolerated by the fish, normal acceptable operating range is between 10‐20 ppm.
Getting Ready to Build the System – Sourcing the Components:
So now that you understand the basics of Aquaponics, it’s time to build the aquaponics home system. There are literally thousands of variations and modifications that one could make for an aquaponics system. The model herein proposed aims to produce a high‐yield crop with minimal maintenance and care on a minimal amount of space, indoors or outdoors. The first step after having reviewed this manual, is to source the parts. There are three part components to the system: Fish, Plants, and Hardware:
A variety of freshwater fish can and have been used for aquaponics systems, including carp, goldfish, trout, smallmouth bass, largemouth bass, catfish, and tilapia to name a few. In the United States and Canada, local regulations allow for the growing of certain of these freshwater fish, so you will need to check with your local University, Agricultural Extension office, or even pet store to determine what you can use in your specific geographical area. The decision now is whether to buy Fry or Fingerlings. The fish fry will cost you less, but they will take longer to mature, which equates to a longer time to reach adequate nitrate levels and system optimization. Conversely, although the fingerlings will be more expensive relative to the fry, they will be churning out more excrement early on during the system optimization process, which in turn equates to an earlier start on growing vegetables. You decide. You can even locate a local aquaculturist and buy mature fish directly. Beware of adding Fry to adult fish; they may be eaten. So, in case you are contemplating to raise your own fish, use a separate hatchery tub.
Based upon your decision surrounding your choice of fish, and the stage of their maturity, you will now need to give thought to your plants. The aquaponics system can be a float-based system, and you can either start your seedlings already in the floats or you can transfer the shoots from a seedling bed attached to the system (an option for which your plans here allow) or from a conventional seedling tray. At this point, a quick discussion of a float system (also known as “raft” systems) is relevant.
In a raft system the plants are grown on Styrofoam boards or similar material that float on top of water. In most cases, this tank (the grow bed) is separate from the fish tank. Water flows continuously between the two tanks. The beneficial Nitrosomanas and Nitrobacter bacteria live throughout the system. Their biology is such that they need a substrate – or surface – on which to attach for the life cycle. This ends up being the walls of the tank, the pipes, the underside of the floats, and, interestingly enough, the very roots of the plants themselves. Having a separated raft tank provides extra benefit in that the raft tank provides an added buffer for the fish (in terms of water quality and quantity), reducing stress and potential water quality problems. This is one of the greatest benefits of the raft system. Raft / float systems optimize floor space and maximize growing space, which in the case of our aquaponics home system, makes. It ideal for beginners who have limited space.
To maximize the system, you want to opt to sprout your plants in a separate grow bed and only transfer them once the roots are long enough to become part of the grow bed. As for the starter medium for the seedling pots, we recommend coconut fiber. It holds both water and air very well and is a great natural organic choice. Use net pots filled with coconut fiber and place the seeds inside. Then, water twice a day, ideally with the nutrient‐rich aquaponics water. Thin out the seedlings and delight in the young life!
Once the seedlings have reached maturity – generally 2‐3 weeks for leafy greens – you will transfer them to the grow beds. You will quickly learn the grow times and maturation times of the various plants that you select to grow.
Have fun, experiment with different varieties and combinations. The goal is to have a continually rotating crop base that is constantly yielding while seedlings are growing.