Aquaponics systems often require fish that provide an important protein source, like tilapia, which increases costs and complexity through requirements for extensive services, permitting, and knowledge of fish aquaculture. However, using ornamental fish instead could increase the likelihood of project success as they are cheaper and easier to cultivate, feed, and provide waste. This study tested a backyard raft aquaponics system using goldfish or koi as the waste source, and found that koi provided better crop growth than goldfish, with no significant difference between using LED lights or sunlight.

1. AQUAPONICS AND AQUACULTURE GOING BACK TO BASICS
D. V. Robertson-Andersson; C. Haripursad; N. Padayachee
robertsond@ukzn.ac.za
University of KwaZulu-Natal; College of Agriculture, Engineering and Science, School of Life
Sciences; Durban, KwaZulu-Natal, South Africa; Private Bag X 54001, 4000
ABSTRACT
Aquaponics has been touted as the solution to global water consumption caused by human population
growth and development and aquaculture has been called the blue revolution for its ability to feed the
masses cheap protein. Yet the South African Aquaculture landscape is littered with failed projects.
Aquaponic systems although cheap and easy to build often require the fish to be an important protein
component of system and this usually involves Tilapia or other production fish. This means that
extensive extension services like feed hatcheries etc., knowledge of fish aquaculture, permitting and
EIA are required increasing the cost and difficulty of such projects. However if we remove the protein
source and replace it with a cheap, simple, easy to cultivate, feed and obtain waste source like
ornamental fish, then this increases the likelihood of project success. Ornamental fish are an example
of leapfrog technology in that they are numerous smaller breeders connected to one larger distributer,
the feed, fish and systems are cheap and easy to obtain. This study tested the effect of LED light
versus sunlight on a backyard raft aquaponics system using gold fish or ornamental fish as the waste
source for the aquaponics systems. Plant growth and water quality between the four systems were
tested over 3 harvests. Koi fish gave better crop growth than goldfish and there was no significant
difference between LED and sunlight on plant growth. This research provided knowledge on the
application of aquaponics to leap frog technology and the economic benefits of aquaponics.
KEYWORDS: Aquaponics, ornamental fish, goldfish, koi fish, leapfrog technology