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      Fact Sheet 5.02  

What  is  it?    

Aquaponics  is  an  ecosystem  approach  to  growing  food.  It  is  a  relatively  new  technology  combining  hydroponics  and  aquaculture  (growing  fish  in  tanks)  with  water  from  the  fish  tank  circulated  through  the  grow  beds,  where  bacteria  on  the  gravel  and  clay  balls  transforms  the  toxic  fish  waste  into  beneficial  nutrients  which  the  plants  take  up  from  the  water.  

How  does  Aquaponics  work?  

In   hydroponics,   the   plants   feed   on   chemical  nutrients   placed   in   the   water.   In   aquaponics,  chemical  nutrients  would  kill  the  fish  and  so  only  organic  feed  can  be  given  to  fish  and  only  organic  fertilizers  used.  As  well  as  standard  fish  food,  the  fish   will   eat   worms   and   insects.   Some  practitioners  are  experimenting  with  black  soldier  fly  larvae,  duckweed  and  azola,  as  well  as  minced  carp  meat.  

 

 

 

 

Advantages  

Aquaponics  uses  only  10%  of  the  water  required  to  grow  plants  in  the  open  field  situation.  Even  in  arid   areas   it   can   operate   using   rainwater  collected  from  the  roof  of  the  system.  It  does  not  need   fertile   soil.   It   is   low-­‐tech,   uses   relatively  little   energy   and   requires   relatively   low   capital  input.    Aquaponics  does  not  require  fertile  soil  or  abundant   rainfall   and   can   operate   therefore   in  areas  with  low  or  unreliable  rainfall.  

 

What  will  grow  in  aquaponics?  

Virtually   any   freshwater   creature   –   trout,   perch,  murray   cod,   barramundi,   yabbies,   marron,   eels  etc  –  can  be  raised.    Temperature  of  the  water  is  a  major   factor:   trout  are  easier  to  raise   in  a  cold  place   like   Canberra;   barramundi   do   well   in  warmer  climates.  One  can  heat  or  cool  the  water  to   suit  particular   fish  but   this  may  be  expensive.  Fish   fingerlings  are  available   locally,   but  a   cheap  and  reliable  way  to  start   is   to  use  carp  caught   in  the  local  lakes  or  rivers.

Aquaponics  

Biointensive  Gardening  addresses  the  Permaculture  Principals  –  Integrate  rather  than  segregate,  obtain  a  

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For  further  information  on  this  topic    DIY  manuals  are  available  and  the  internet  has  lots  of  information.    Locally,  Fusion  Australia  Canberra  Office  will  demonstrate  its  double  garage  size  system  (tel  :  6162  3700).  

A   wide   variety   of   vegetables   can   be   grown.  Tomatoes,   lettuce,   eggplant,   green   vegetables,  capsicum   and   herbs   are   popular   as   are  strawberries.  In  tropical  areas,  small  trees  such  as  paw   paws   can   be   grown   and   forage   for   cattle.  Most   aquaponic   operations   are   located   in  glasshouses   or   plastic   tunnels,   but   it   is   possible  also  to  grow  vegetables  in  grow  beds  in  the  open.  

Size  of  systems  

A   “balcony”   system   would   cover   about   five  square  metres.   A   3,000   litre   fish   tank   plus   grow  beds   would   fit   into   36   sq   metres,   the   size   of   a  double   garage.   Commercially,   glasshouses   could  range   from   a   small   business   size   of   say   500   sq  metres  up  to  complexes  of  30  hectares  or  more.    

A  3,000   litre   fish  tank  system  could  produce  fish  and   vegetables   worth   $1,500   or   more.   Large  systems   could   give   a   gross   annual   return   of  between   $1   to   $1.5   million   per   hectare,    depending  on  what  you  are  growing.  

 

Costs  

The  capital  cost  of  a  backyard  3,000  litre  fishtank  system  could  be  $2,500  off   the  shelf.  You  would  reduce   costs   considerably   if   you   used   recycled  materials   such   as   old   bath   tubs   and   drums   and  built   the   system   yourself.   Both   the   construction  and  operation   is   fairly   low-­‐tech.  Ball  park  figures  would  be  between  $1  and  $2  million  to  construct  and  equip  a  one  hectare  operation.  

Future  development  

More   people   are   becoming   interested   in  aquaponics  in  Australia  and  overseas.  Australia  is  reputed   to   have   possibly   the   highest   level   of  expertise.   The   basic   operations   are   quite   simple  but   virtually   every   backyard   practitioner   will  proudly   tell   you   about   a   significant  modification  they   have   made.   The   current   technology   is  probably   in   an   early   stage   of   its   ultimate  development.  Aquaponicists  are  pioneers!  

Aquaponics  for  a  hungry  world According   to   the   TIME  magazine   cover   story   18  July   2011:“…   over   the   past   few   decades,  aquaculture   has   grown   faster   than   any   other  form   of   food   production”.   Australian   science  journalist,   Julian   Cribb,   has   stated:   “   …  aquaculture     will   become   one   of   our   largest  industries”.      

World   population   is   galloping   from   7   billion   in  2013   towards   9   billion   in   2050.   But   most   food  production   in   Australia   and   overseas   is   either  stable   or   in   decline   because   of   declining  productivity   of   the   soil,   rising   fuel   and   fertiliser  costs,   fewer  farmers  and   farm   labourers   -­‐   to  say  nothing  about  climate  change.    In  a  world  rapidly  running   out   of   surface   and   aquifer   water  supplies,   paradoxically,   the   technologies   capable  of   significantly   and   quickly   increasing   food  production   –   of   fish,   fruit   and   vegs   -­‐   are  aquaculture   related,   ie   aquaponics,   hydroponics  and  fish  farming.    Even  Canberra  faces  a  food  security  problem.  But  700   hectares   of   aquaculture   in   and   around   the  city  could  produce  possibly  one  third  of  our  fresh  food.   That   would   take   up   a   total   area   equal   to  about   the   area   of   Weston   Creek,   or   half   the  Woden   Valley.     A   surprising   suggestion,   perhaps  but  not  unrealistic…and  it  may  turn  out  to  be  the  only  way  to  go!