A lot has happened in the past few weeks. Joe got the go-ahead to start constructing the passive solar/aquaponics greenhouse, so that has been his main focus.Thus, Joe passed the maintenance of the lab aquaponics system to me (and some volunteers from other crews at RAD to cover for the days when I am not on the job site). Needless to say, I am becoming rather familiar with our aquaponics rig. I even introduced our fish into the system! That’s right, we have fish!
Now, a bit on the basics of aquaponics. I gathered a fair amount of info on the concept from Joe through out the summer. Now, as I maintain the system, I am learning even more. So, let me share some of my understanding with you.
Aquaponics is, essentially, the fusion of two different agricultural practices: Hydroponics, and Aquaculture. There is a near perfect symbiosis between these two practices. It creates a “closed loop” of energy and nutrients. The plants benefit the fish and the fish benefit the plants. I repeat, perfect!
Okay, so there are three basic “living” elements in an aquaponics system: fish, plants, and bacteria.
The bacteria are typically the first form of life that one needs to develop in an aquaponics system. They are tasked with the job of converting the waste of the fish from ammonia to nitrates! This is why they are often referred to as a “biofilter”.
Running an Aquaponics system without a biofilter present will result in a system with dangerously high ammonia and PH. This is hazardous for all living beings within the system. However, if the bacteria are present, the plants will be able to absorb the nitrates as nitrogen, which will boost their health and growth rates. The plants also help to filter and clean the water for the fish.
Now, that is the general concept. Each aquaponics rig is extremely site specific. Inside or Outside? How many fish? What breed? How much tank space do they need? What is their projected ammonia output? Ecological agriculture is based on connections. We need to train ourselves to spot each connection and test its authenticity and its contribution to the system. Right now, our PH is on the low side for our shubunkins, but it is gradually rising. Joe learned that each system usually settles on its own PH equilibrium over time. Our nitrates are low. Is this because the fish are not producing enough ammonia? Is it because we have a lot of plants that are fruiting right now? The only way to figure it out is to test different treatments and monitor the results. This seems proper. We are learning from our experiment.
This brings me to a closing point. Agriculture in America is generally focused on procedure as scripture. There is very little room for creativity on our farms today. Maybe that is why a lot of people feel initially turned off by sustainable agriculture that focuses on ecology and nature as a guide. Those who are maintaining the systems have to think on their feet instead of follow rules that have been set in stone by people who are obsessed with output.
Looking forward: more general updates about aquaponics, new about our other projects, a list of cool resources about urban agriculture, and diy project ideas!
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