Aquaponics (archived - 2012)
| This page is archived as its information is no longer current. Last update: in June 2012. Current information on this subject can be found at nowhere. |
Project Page
Several members of protospace have undertaken designing, constructing and operating a live aquaponics system in Calgary.
Aquaponics
Aquaponics is a system who's aim is to emulate the natural cycle of growing food as closely as possible. It uses a combination of hydroponic growing with fish care to create a (almost) closed loop system. Basically, fish food is added to the tank, the fish eat it. The fish waste is used to fertilize the plants. Water is recycled in the loop. In a perfect system, the extra plant mater that isn't used by humans could also be used as fish food. A full explination on the Nitrogen cycle can be found here
Lighting
Natural light is great, but it's not always available. Maybe your house doesn't face south, maybe you live in a cave. Either way, light is how plants do their thing and it also takes a lot of energy. Current lights can easily draw 1000W and cost a hundred dollars. I think we can do better than that. Plants have a very narrow spectrum where they absorb light; so white light isn't really necessarily. With LEDs, the correct spectrum can be used thus creating a more efficient system. If we really want to get fancy, we could liquid cool the LEDs and use that heat to keep the fish at the proper temperature.
Luminous efficiency of various light sources
Monitoring Progress
There are many different things that need to be monitored. Nutrient and pH levels, temperature, flow rates, luminosity and so on. We are going to need some micro controller wizards to whip up some code to keep track of all these data points and log them. We can't figure out our efficiency without numbers. Once we have data we can start comparing it to other systems and tweak as necessary.
For an example as to why monitoring is important, fish and plants need different pH levels, so it must be monitored to keep it in habitable zones for both.
Tweaks
There are many different pumps, tanks, filters and systems out there. Should we use a gravity system or multiple pumps? How are we going to deal with heavy metals? What about bacteria? (Good and bad)
All sorts of questions since this is a relativity new science. That's what makes it awesome.
System Risk Factors
- Pest infestation
- Microbial infection (pythium, et al)
- Nutrient factors (pH, oxygenation, chemical concentration(s) of ammonia, etc)
- Outside contamination (mishandling, foreign introduction of organic or inorganic material)
- Systemic shock (spikes or troughs due to temperature controls, nutrient issues, stress etc)
Significant research data exists regarding an aquaponics research project in Brooks, Alberta conducted in 2003-2005 (insert citation to CDC Brooks project, Savidov et al 2003-2005). Of particular interest is the team's findings regarding plant yield compared to organic soil-based production and current mainstream hydroponic production in Alberta.
The study found plant yields were "considerably higher than average in organic greenhouse production based on soil, but still 15% - 25% lower than average yields in mainstream greenhouse vegetable production based on hydroponics." (insert citation to CDC Brooks Project, section 3.1.2.1). The research document further examines the potential causes, notably a "lack of experience resulted into a massive loss of plants caused by disease and pest infestation during winter period 2003-2004."
Further research reveals a local strain of Pythium Aphanidermatum was largely responsible for major plant loss, including mention of prevention measures to adopt in the future. As a result, plant yields exceeded the industry average in 2004/2005, over the previously observed performance in 2003/2004 (reference Figure 3 and 4 in CDC Brooks project, page 14 and 15).