Last update: 08.16.2011
"Aquaponics is the integration of aquaculture and hydroponics. An aquaculture is used to continuously generate a nutrient-rich solution to feed a hydroponic garden. Aquaponic systems can be used to replicate controlled wetland conditions that are useful for reclaiming potable water from typical household sewage, in addition to generating a continual supply of food with minimal fertilizer use. Aquaponics, which takes advantage of synergy between self-organizing biological systems, is a key element of permaculture. This synergy benefits both systems and allows each to help maintain the other. For example, an aquaponic system consisting of goldfish and watercress would require less human intervention into each system. The goldfish would benefit from the filtration carried out by the watercress, and the watercress would benefit from the nutrient-rich waste excreted by the goldfish." - old Wikipedia entry
A good book about planted aquariums is "Ecology of the Planted Aquarium, A Practical Manual and Scientific Treatise for the Home Aquarist" by Diana Walstad. The book is not strictly about aquaponics, but is definetly related.
Other good resources to research are constructed wetlands which work on the very same principles, except that constructed wetlands don't generally crop for food. Also, the design of chinampas is another very similar system.
These are just my notes and experiments to find what works for me.
terraced indoor window system
This is a new experimental setup I am playing with for growing in front of a large window indoors. I am basing my flora on what is appropriate for my climate and latitude, which may be different for others. My design is also appropriate to my individual situation, which is limited space indoors and the need to grow vertically.
solar powered aquaponic system diagram
This diagram is not drawn to scale, and I would recommend at the least 12 inches of bed depth.
Using a nozzle at the end of the tubing, supplying the water to the plant bed, increases the pressure of water and creates a more turbulent, highly aerated zone. If the high pressure flow is fed into a pool of water, the sound that is created is similar to white noise. Although, evaporation rates will be higher.
I threw the thermocoupling into the diagram just for fun. It would be nice to transfer the heat from the panel into the tank. The thermocoupling would work most efficiently if the water was fed directly against the panel, like a CPU cooler.
To conserve energy, a timer, to control the pump, could be added. This would also create an ebb and flow system. The timer could be set to pump every other hour, for a total of 12 hours a day, rather than continuous 24 hour pumping. An ebb and flow system is advantageous for plants that do not like to be submerged for prolonged periods. Or a bell siphon could be used for ebb and flow as well, which is continuously pumped.
A ceramic or clay based bottom maybe advantageous if it were to act as a distributed heat plate. Plus, the ceramic's porous structure would possibly benefit the growth of smaller organisms.
flooded aggregate plant bed
The bed is the filter. The filter is the bed.
Sandstone or the commercial product Hydroton makes a superb media for the planted bed, for it's porous structure and ability to absorb water. Any type of gravel works, but it gets heavy. I prefer to use a media that is rounded somewhat. When digging with your hands in sharp stones, it can hurt and is not pleasant, and if you use a pond liner for your planted bed there is always the possibility it may tear. Porous media will give you the greatest surface area which is key for the growth of beneficial bacteria. Use what is most easily available.
tank
- 12in. x 12in. x 36in.
- 5184 sq. in
- 22.44 gallons
- 84.95 liters
tank flow
Here are several configurations for possible tank circulation schemes.
The longer rectangular tank mimics the flow of a stream and is most likely the fastest flowing of the three. The circular tank is more akin to a pond. And the last combined configuration is probably my favorite as it is the most dynamic. It allows for an inner pond with slower stagnant water which is advantageous for plants which prefer that or even may be a place for fish to breed. The inner island of the combined configuration allows for many possibilites. It also creates a greater edge and an interface between fast water and slow water.
tank pump
I am using a Danger Den DD-CPX Pro 12 volt PC cooling pump with 1/2" barbs. It is holding up quite well and is very quiet and compact. I chose a PC cooling pump because it will allow me to control it if I ever decide to implement a computer controlled system.
The pump should be arranged so as not to allow noise and vibration to contaminate the fish tank. Pumps installed within the tank are noisy in the fish environment, possibly stressing the fish. I have no scientific proof of this, just my experience. I wouldn't want to listen to the hum of a pump constantly for my entire life.
Since I am using a pump designed for PC cooling which has to be primed, I have placed it below the water table so gravity primes the pump.
| Name: | Danger Den DD-CPX Pro |
| Rated voltage: | 10.8 - 13.2 Volts DC |
| Load current: | 1.8 Amps |
| Consumption: | ~ 18 Watts |
| Q-max: | 800 Liters per hour |
| Noise: | under 25 decibels |
bell siphon
Ahh, the mysterious bell siphon. The bell siphon is the muscle that controls the breathing of the planted bed.
These are the traditional bell siphon designs, which I tested to understand it's principles.
Once I had a grasp on how the bell siphon worked, I decided to experiment with something more simple. Placing the appropriate size bag over the top of a bottom slotted pipe worked amazingly well. I call it the bladder siphon. The bag should loosely fit over the pipe. Cheaper, no silicone, less work, lighter, easier to adjust, and more quiet. I used a bag that some zip ties came in. The bladder is also much more visceral, as you can watch how gases and liquids are being exchanged. This makes me wonder if a two bladder setup over the standpipe would work. I should probably use a food grade bag as well.
I am always striving in aquaponics to simplify and mimic nature. I am sure I can find a better fitting bag without kinks and the like, maybe the bag the fish came in, a large balloon or a condom...
various outlet pipes
Here are several outlet pipes that I made to experiment with the flow of water from the bed to the tank. I enjoy watching the fish play in the current that is created by the out flow. I setup my outlet and inlet on tangent so as to create a circular flow in the tank, helping to mix everything.
I prefer the slotted design. It seperates the water into thin sheets and provides a much better surface area interface between the water and the air. I also like the sound of it. The slot design seems like it may benefit the fish, as the sheet of water that is output is very similar in size to the actual fish, rubbing against the side of their body more evenly. This is just an observation I have made, and I have no conclusive evidence. The slot design is also very similar in shape to the lamellae within the gill of the fish. I love details like this. Peeing in the fish tank...
This outlet has a series of 1/4 inch and 1/16 inch holes. It has a very farty sound.
This outlet has a lot of 1/16 inch holes and provides a more fine stream of water. It tends to get clogged.
plants in flooded bed
| Common name |
|---|
| Arugula |
| Chives |
| Cucumbers |
| Snap peas |
plants in still tank
I use a still tank to grow fish food. When I started the still tank I seeded it with river water full of tiny microorganisms. There are snails and other various tiny critters feeding on a lot of the dead organic matter in there. The still tank is not connected to the main aquaponic system. Although, at some point I would like to integrate it.
| Common name | Scientific name | edible |
|---|---|---|
| Arrowhead (duck potato, wapato) | Sagitarria latifolia | tubers |
| Bog bean (buckbean) | Menyanthes trifoliata | leaves |
| Duckweed | Lemnaoideaa | all |
| Water celery (Japanese parsley, chinese celery) | Cryptotaenia japonica? | all |
I make no claim as to the accuracy of my notes on these plants. Plant taxonomy is very messy.
fish
Tilapia, carp, etc...
filter notes
further work
- Implement a mini-itx board for control.
meta-thoughts
For a designer, be it lighting, graphic, or what have you, one requisite seems to be the use of filters. After pondering the optimal throughput and ease of use of this biological filter, I could not tear myself away from thinking about all the different types of filters. Lens filters, photoshop filters, spam filters, notch filters, audio filters, media filters, the filter in your Brita or your Mr. Coffee, or your kidneys...
Generally the filter is thought of as mechanism through which to remove material harmful to the system it is acting within. Yet, when one uses a photoshop filter, one primarily doesn't think of it as removing something harmful, but as a means to achieve a certain aesthetic or creative end. Could the original image be deemed as harmful? Harmful to the creative practice? Or is this mere semantics?
Biological filters are most effective when the material to be processed is passed through a hierarchy of stages, the first being a coarse aggregate, then less coarse, all the way through to a very fine aggregate. This lead to me a wider understanding of information control structures. Many people and organizations use news aggregators and the sort to specifically tailor their information uptake, so as to remove unwanted stories, headlines, etc., basically to remove noise, to tune in.
Tuning in, in the early days of radio, meant adjusting of the radio's coil so as to obtain the optimal level for listening enjoyment. Musicians tune their instruments. Timothy Leary's famous phrase "turn on, tune in, and drop out". Or your late night talk show host reminding you to stay tuned. Now we have the all to familar iTunes. With the advent of digital technologies, the art of tuning is slowly being relegated to that of ham operators and classical musicians. With computers calculating quantization errors, the art of the tune is lost. The true sine is thus a blocky interpretation. The digital / analog divide.
Is tuning synonymous with filtering? Filtering removes substance, tuning changes the characteristics of the substance?
plants in space
Aquaponics always gets my mind thinking about plant life on space ships. This eventually leads me to thinking of the water weight and how this water is stored on orbitting vessels. Is the water stored as a skin layer around the space ship? Is the space shuttle a vacuum sealed thermos?