Creating An Aquaponic System

Posted by Cathy Green on

Establishing the size of the system

  • You will need at least two containments. One for the fish tank and one for the grow bed.  Most people use a poly tank, but bath tubs or half barrels can be used as well. Stay away from anything galvanized or metal which is not conducive to fish growing. 
  • Fish- Grow Beds - Fish Tanks rule of thumb

1 lb( 500 gram ) or  8 in  of fish for every 1 sq ft grow bed. (12 inches deep)

1 lb of fish for every 5-7 gal

 So -100 gal tank  14 fish  growing bed -7 x2


Plumbing the Aquaponic System

Aquaponics uses a basic flood and drain design. 

  • Circulate the water from the fish tank through the grow bed. And drain it back into the fish tank.
  • You can use a trickle down method or percolate up through your grow beds. Water can either spill over a spillway back into your fish tank or your can plumb it in line in a closed system. 
  • In a closed system water is drained either through the back flow on the pump or through a smaller drain than the intake on the grow bed. 
  • Flood the grow bed on a a timing cycle of 15 minutes on and 45 minutes off . This will filter the water well and allow for sufficient drying time for the plant roots.
  • Use a pump size with the flow rate of four times the tank and you will eventually circulate the entire tank every hour. 
  • The easiest process to achieve the timing cycle is with a programmed timer on your pump.
  • Some grow beds use an auto siphon or bell siphon to create their drain cycle. Instructions to make your own bell siphon are on the internet. 
  • Most grow beds are 12 inches deep although smaller plants such as lettuces and herbs will grow well in a more shallow depth.  

Growing Media

  • There are different types of growing media that can be used for your grow beds. Media for your grow bed is either gravel or expanded clay.
  • You do not want to use media that will effect the pH of the water or is capable of breaking down.
  • A good size media to use is half to three quarters of an inch in diameter.
  • A more porous media with a lot of surface area is advantageous for bacteria to grow and convert the waste of fish to the beneficial nutrients needed for the plants.
  • Always wash the media off first before adding it to the system..
  • Grow beds that are larger than eight sq. ft. may use a manifold to circulate the water through your media evenly and keep water from channeling around a clogged up area in the grow bed.  
  • The Aquaponic grow bed is best understood by root zones. The zone 1 or first 2 inches of surface is best left as a dry zone. This will protect plants from algae growth and moisture related disease The zone two or the next 2/3  of growing depth is the root zone. This is where the flood and drain cycle allows the delivery of oxygen rich air to the roots as well as the  beneficial bacteria and even worms for breaking down solids . The bottom zone 3 is where fish waste and solids are collected.

Aquaponics and Grow beds and Fish tank

Rule of thumb

1 lb( 500 gram ) 8 in  of fish for every 1 sq ft grow bed. (12 inches deep)

1 lb of fish for every 5-7 gal

100 gal tank  14 fish  growing bed -7 x2

30 gal 4-5 fish  growing bed 2x2