Aquaponics

R.GobirajBSc in Fisheries Science,University Of Jaffna,Sri Lanka.

Contents Introduction History Essential components of an Aquaponic unit Water quality in Aquaponics Aquaponics Plants and requirements Aquaponics Fishes and requirements Functioning of Aquaponics Aquaponics in Sri Lanka Advantages and disadvantages Other Possibilities in Aquaponics Conclusion Reference

Introduction Aquaponic is a fast growing and more sustainable method of food

production. Aquaponics is a system that combines hydroponics with intensive

aquaculture bio-integrated food production system.

Historyhydroponics Hydroponics is the production of plants in a soilless medium where by all of

the nutrients, which are supplied in aqueous solution

In China it was reported that "frame fields" for growing water spinach were

widespread in ancient times

The raft gardens were made with a frame of bamboo and a layer of soil and

supplied leaf vegetables for home consumption

In Mexico and Bangladesh organic matter from plants was used to create rafts

for floating agriculture

ChinampasBuilt by Incas and Aztecs Between 14th -16th century A.D

intensive aquaculture intensive aquaculture in which fish are kept at high density in tanks or

raceways and fed a high quality food US only since the mid-20th century As production intensified it was realized that the effluent was high in nutrients

and could cause eutrophication and other environmental impacts

Aquaponics it has an ancient history, Plants have been grown using fish farm wastes either directly or

indirectly in China and SE Asia for thousands of years aquaponics has been strong since the 1960s, in US at Woods Hole Oceanographic

Institute awareness of impact of nutrient wastes on the environment while at the same time

increasing the requirement of food production developed the aquaponics Globally there are now hundreds of small scale aquaponic initiatives and several larger

scale commercial or near commercial enterprises

Essential components of an aquaponic unit

fish tank

mechanical filter

bio filter

hydroponic containers

Water circulation unit

aerators

fish tank essential component in every unit Shapes

round Square Oval

material plastic Fiberglass Cement ground pond

Colour White or other light colours

mechanical filter separation and removal of solid and suspended fish waste from fish

tanks

It is essential for the health of the system

Type of filter

Screen filter

sedimentation tanks

sand or bead filters

Bio filter The bio filter is installed between the mechanical filter and hydroponic

containers

living bacteria

Nitrosomonas

Nitrobacter

volcanic gravel, plastic bottle caps, netting, PVC, shavings and nylon scrub

pads are act as substrate for bacteria

Nitrosomonas bacteria convert ammonia (NH₃) into nitrite (NO₂-)

Nitrobacter bacteria then convert nitrite (NO₂-) into nitrate (NO₃-)

Hydroponic components the plant-growing sections in the unit Three designs are more familiar with aquaponics

media bed /particulate beds

nutrient film technique (NFT) deep water culture

Water circulation unit Water circulation is fundamental for keeping all organisms alive in

aquaponics

The water moves from the fish tanks, through the mechanical filter and

the bio filter and then to the plants in their media beds and finally to the

collecting tank

Water quality in aquaponics Oxygen pH Temperature Ammonia Nitrite Nitrate Water hardness

oxygen

plants, fish and nitrifying bacteria all need oxygen to live.

fish may die within hours when exposed to low DO within the fish tanks

adequate DO levels is crucial to aquaponics

pH

The pH of the water has a major impact on all aspects of aquaponics, especially the plants and bacteria

the pH controls the plants’ access to micro- and macronutrients

Nitrifying bacteria difficult to survive below a pH of 6, and the bacteria’s capacity to convert ammonia into nitrate reduces in low pH conditions. This can lead to reduced bio filtration and fish mortality

Temperature general compromise range is 18–30 °C. Temperature has an effect on DO as well as on the toxicity of ammonia

high temperatures have less DO and high temperatures more unionized (toxic) ammonia

Ammonia Most of the fish waste is form of ammonia (NH3) ammonia is then nitrified by bacteria and converted into nitrite (NO2-) Ammonia is toxic to fish, Commonly in fishes can show symptoms of ammonia

poisoning at levels 1.0 mg/ liter high level of ammonia damage to the fishes’ central nervous system and gills

Nitrite

High levels of NO2- can immediately lead to rapid fish deaths.

Again, even low levels over an extended period can result in increased fish

stress, disease and death

NO2- prevent the transport of oxygen within the bloodstream of fish its

called as brown blood disease

Nitrate

Nitrate is a far less toxic than the other forms of nitrogen It is the most accessible form of nitrogen for plants, and the production of

nitrate is the goal of the bio filter

Fish can tolerate levels of up to 300 mg/ liter.

Aquaponics Plants and requirements most popular vegetables are leafy vegetables and herbs-especially lettuce

and basil less suitable for fruit vegetables suitable vegetables

Lettuce Basil Spring onion Fruit vegetables such as tomato, cucumber Beets Okra Blueberries

Plants require sunlight, air, water and nutrients to grow Essential macronutrients include: nitrogen, phosphorus, potassium, calcium,

magnesium and sulphur Micronutrients include iron, zinc, boron, copper, manganese and

molybdenum Deficiencies need to be addressed by supplying the limiting nutrients with

supplemental fertilizer or increasing mineralization The suitable temperature range for most vegetables is 18–26 °C, although

many vegetables are seasonal. pest/disease management uses physical, mechanical and cultural practices

to minimize pests/pathogens uses fish-safe chemical and biological treatment in targeted applications,

when necessary

Aquaponics Fishes and requirements High tolerance and high marketable fishes are more suitable

Tilapia, carp, and catfish are highly suitable for aquaponics

Common culture fishes Tilapia Catfish common carp (Cyprinus carpio) Mullet perch bester sturgeon grass carp

Tilapia

possibilities

preferred species for tropical and sub-tropical situations

easy to breed

tolerates low Dissolved Oxygen (DO) levels (0.2 ppm)

high Total Ammonia Nitrogen levels (>90 ppm @ pH 6.0)

low pH levels (< 5.0)

Problems

It will breed very readily

Breeding will reduce fish production rate/quality

Requirements

the correct balance of proteins, carbohydrates, fats, vitamins and minerals

needed for fish

never overfeed the fish, and remove uneaten food after 30 minutes

Poor / changing water quality, overcrowding, and physical disturbance can cause

stress

which may lead to disease outbreaks

Take the time to observe and monitor the fish in order to recognize symptoms

early and provide treatment

Functioning of Aquaponics

Hydroponics

Bacteria

Aquaculture

Functioning of Aquaponics ….

The Aquaponics cycle

Aquaponics in Sri Lanka

In Sri Lanka aquaponics introduced as a Agriculture Tourism

E.g - Gadadessa is a Holiday Resort in Kandy

Advantages Reduced labour

Aquaponics uses 90% less water than traditional farming

NOT require farm land and soil

Fish feed is the only nutrient inputs

Aquacultural waste products are used

Aquaponics protects our rivers & lakes

Health & Nutrition value high

Higher production rate

Provides income from two separate products

A lot of current research and improvements going on

Disadvantages High initial cost

To fill up water tanks To build the system (Greenhouse, pumps etc.)

Difficult to grow root crops Requires skill and experience Constant monitoring of water parameters Pests and diseases can be devastating Limitations concerned with fish species reared Competitive market prices Requires electric energy to maintain and recycle water within the system

Other Possibilities in AquaponicsOrganic Aquaponics Natural fertilizer Natural minerals (snail shells) Good marketing – labelling

Use of Technology Smart phone applications Pipe blockage warning System automation

Other Possibilities in AquaponicsGrowing Indoors

Can be used underground and indoors

Artificial lighting

Other Possibilities in Aquaponics ……

Growing Upwards

Futuristic Concepts

Growing locally

Dedicated Skyscraper

Farms

Makes use of limited

space availability

Space missions

Conclusion Aquaponics is a more sustainable food production systems It involves the production of both fish and vegetables, using

a single nutrient source (fish feed) however that aquaponic systems are primarily vegetable

production systems, simply because of the biological nature of the relationship between fish nutrient production and plant nutrient uptake

The primary advantage of aquaponics is water use efficiency. Other oft-cited advantages include nutrient utilization efficiency, product quality and food security

Reference Bakhsh, H.K. (2008) Integrated culture, Hydroponics &Aquaponics systems. Universiti

Malaysia Terengganu.

Bernstein, S. (2011) Aquaponic gardening: A step-by-step guide to raising vegetables and

fish together. New York, NY, United States: New Society Publishers.

Long, B. (2012) The EZ guide to aeroponics, hydroponics and aquaponics: [how to create

a sustainable food supply]. Texas: Bonjour Limited Holdings.

Staff, P.S. (2007) Great source aim new jersey: Student edition Workbook 5pk grade 3

(level C) 2007. United States: Great Source Education Group.

Somerville, C. (2014) Small-scale Aquaponic food production: Integrated fish and plant

farming. Rome, Italy, Italy: Food & Agriculture Organization of the United Nations (FAO).

Thank you