First Principles
Hello
and welcome to my fortnightly DigiLetter. It excites and honours me
greatly to be able to share my passion with you in this way. For a
little more context and background about me, please read my introductory interview with DigiLetter.
Aquaponics and its future progression is something I have dedicated my life to. In an effort to help clear up some of the myths and misconceptions surrounding aquaponics, I will do what I can to remain concise. The 'definitive reference' on aquaponics is indeed what I intend to create throughout this series. But if I am short on detail with some things, forgive me — I will endeavour to keep this behaviour relegated only to things that can safely be described as post-requisite (i.e. not core information). So, let us begin.
Aquaponics and its future progression is something I have dedicated my life to. In an effort to help clear up some of the myths and misconceptions surrounding aquaponics, I will do what I can to remain concise. The 'definitive reference' on aquaponics is indeed what I intend to create throughout this series. But if I am short on detail with some things, forgive me — I will endeavour to keep this behaviour relegated only to things that can safely be described as post-requisite (i.e. not core information). So, let us begin.
Introduction: Aquaponics
Fig. 1
The
English noun 'aquaponics' comes to us as a modern marriage of word
units, comprised of the Latin root 'aqua' (meaning 'water') and the
Greek root 'ponic' (meaning 'to toil' or 'to put'). A translation might
be 'to toil with water'. There are many examples of ancient forms of
agroecology that could loosely be described as a 'precursor' to modern
aquaponics. 3500 years ago the Aztecs of South America created raised
mounds inside fenced-off, shallow lakes. By using mud, decaying
vegetation, animal dung and even 'night soil' (human fertiliser), these
damp, microbially active mounds produced a greater yield of food than
other methods available at the time. Indeed, wars were fought over
control of these relatively small areas of land.
6300 years ago, paddy fields were already in use in South-East Asia. As eels, loaches, carp and other species relocated to take advantage of this new environment — and as animal run-off from intensive farming reached the paddies — early farmers could not help but notice the increase in productivity. Early records exist to attest to efforts to maximise this relationship.
Technology is truly a marvelous thing, and Google's incredible 'Ngram Viewer' is amongst the most amazing of all. With over 30 million scanned books (increasing at a rate of 1,000 per day) going back 500 years, anyone can use this tool to investigate the etymology and usage of any term in selected languages. According to this method, it appears the term 'aquaponics' first arose in English literature in 1933. The subject received some mild attention at the time — but this was soon erased by WWII. From this point on there appears to be no further mention anywhere in English literature for another 3 decades. Is this another lesson from history, on the untold costs of war? I should probably think so. Intermittent literary interest appeared again from the 1960s-80s, but even then 5 years could pass without a single worldwide mention of the word in English literature. It appears that aquaponics began its ascent into modern mainstream consciousness around 1990. By the time the internet appeared there was no going back and aquaponics has enjoyed an exponential increase in exposure since.
Modern aquaponics bears little resemblance to the related methods mentioned earlier. Not only do we have access to better materials, but we also have access to science. Today we know that an aquaponicist is primarily a microbe farmer and furthermore we know that microbes are what power aquaponic systems. We know that an aquaponic system is a broad representation of the natural processes at work in a freshwater river. However, it is a representation that must include all surrounding ecosystems and associated biochemical processes — from what goes on below the silt at the bottom of the river to the farthest reaches of the riparian zone. Aquaponics is an exercise in bio-imitation. While we cannot hope to functionally achieve 'closed-loop bio-mimicry' in our own artificial environments, we can imitate the processes that we do understand to achieve the most efficient and functional representations that we can practically manage. We assess where our loops are not 'closed' in our aquaponics system and do what we can to mitigate them. Though a subject for another edition, feeding the fish in a sustainable manner is the largest of 'unclosed' gaps in aquaponics. Electrical input is another.
6300 years ago, paddy fields were already in use in South-East Asia. As eels, loaches, carp and other species relocated to take advantage of this new environment — and as animal run-off from intensive farming reached the paddies — early farmers could not help but notice the increase in productivity. Early records exist to attest to efforts to maximise this relationship.
Technology is truly a marvelous thing, and Google's incredible 'Ngram Viewer' is amongst the most amazing of all. With over 30 million scanned books (increasing at a rate of 1,000 per day) going back 500 years, anyone can use this tool to investigate the etymology and usage of any term in selected languages. According to this method, it appears the term 'aquaponics' first arose in English literature in 1933. The subject received some mild attention at the time — but this was soon erased by WWII. From this point on there appears to be no further mention anywhere in English literature for another 3 decades. Is this another lesson from history, on the untold costs of war? I should probably think so. Intermittent literary interest appeared again from the 1960s-80s, but even then 5 years could pass without a single worldwide mention of the word in English literature. It appears that aquaponics began its ascent into modern mainstream consciousness around 1990. By the time the internet appeared there was no going back and aquaponics has enjoyed an exponential increase in exposure since.
Modern aquaponics bears little resemblance to the related methods mentioned earlier. Not only do we have access to better materials, but we also have access to science. Today we know that an aquaponicist is primarily a microbe farmer and furthermore we know that microbes are what power aquaponic systems. We know that an aquaponic system is a broad representation of the natural processes at work in a freshwater river. However, it is a representation that must include all surrounding ecosystems and associated biochemical processes — from what goes on below the silt at the bottom of the river to the farthest reaches of the riparian zone. Aquaponics is an exercise in bio-imitation. While we cannot hope to functionally achieve 'closed-loop bio-mimicry' in our own artificial environments, we can imitate the processes that we do understand to achieve the most efficient and functional representations that we can practically manage. We assess where our loops are not 'closed' in our aquaponics system and do what we can to mitigate them. Though a subject for another edition, feeding the fish in a sustainable manner is the largest of 'unclosed' gaps in aquaponics. Electrical input is another.
In
Figure 1 we can see a simplified representation of the aquaponic cycle.
In practice, all processes are permanently ongoing and have no specific
order. The ultimate goal is clean but nutrient-rich water, healthy
plants and healthy fish — combined in the same, semi-closed system. As
you might begin to suspect, this is not quite as easy as it first sounds
— or as 'simple' as many might want to promote. Having said that, I
enjoy great success and you can too. With aquaponics, surpassing the
output of traditional, similar sized soil gardens is a cinch and the
simplest of goals to achieve. Another great thing about aquaponics is
that there are no known aquaponic-specific or related diseases that pose
a serious health risk to humans. The same cannot be said for all modern
farming types and methods.
Fig. 2
In
its most basic form an aquaponics system comprises of at least two main
components: a fish tank and a grow-bed for the plants (Fig. 2). As the
fish breathes and metabolises its food, it excretes waste in the form of
ammonia (NH3). The water is pumped up into the grow-bed, where certain
types of microbes live that can use the ammonia in the water as a food
source. By oxidising the ammonia into nitrites and eventually nitrates,
these microbes turn toxic ammonia into plant food — over a period of
some 8-12 hours. In turn, the plants soak up the nitrates and provide
further particulate filtering via their roots. Gravity eventually
returns the water from the grow-bed to the fish tank and the cycle
continues. By investigating the science behind these microbes – who they
are and what they do – we can determine what kind of environment they
need to be able to perform their duties at maximum efficiency. Once
again, this will be a subject for a later edition.
Although in no way necessary for a successful system, I choose to manage my aquaponics systems in a number of very specific ways. Firstly, all of my aquaponic growing efforts go towards growing food. I use aquaponics only to grow edible fish and edible plants. Not surprisingly, this is substantially more difficult than choosing to grow less specific, hardy or non-edible varieties. All types of weeds, reeds, bushes etc. will thrive in an aquaponic system. Similarly, many animal species such as goldfish, loaches, turtles, carp, frogs and tadpoles will also thrive. However, these are not normally a traditional part of my diet. In this respect aquaponics can be more easily managed, by simply choosing to go with a purely aesthetic design, supported by rugged plants and animals. Such designs lend themselves well to situations where phytoremediation (water treatment) is required. However as stated, my focus will be on food.
Although in no way necessary for a successful system, I choose to manage my aquaponics systems in a number of very specific ways. Firstly, all of my aquaponic growing efforts go towards growing food. I use aquaponics only to grow edible fish and edible plants. Not surprisingly, this is substantially more difficult than choosing to grow less specific, hardy or non-edible varieties. All types of weeds, reeds, bushes etc. will thrive in an aquaponic system. Similarly, many animal species such as goldfish, loaches, turtles, carp, frogs and tadpoles will also thrive. However, these are not normally a traditional part of my diet. In this respect aquaponics can be more easily managed, by simply choosing to go with a purely aesthetic design, supported by rugged plants and animals. Such designs lend themselves well to situations where phytoremediation (water treatment) is required. However as stated, my focus will be on food.
