Aquaponics Greenhouse

The The The GreenGreenGreenhousehousehouse The Greenhouse system combines sustainable closed loop crop production with renewable energy

technologies for a truly low carbon solution to the way in which we grow our food.

The greenhouse is multifunctional in that it provides both a diverse and year round supply of high value

crops, but also functions as an interactive participatory learning environment.

The greenhouse is designed to utilise an ecosystem

approach to growing food, utilising wastes as

resources.

• Wastes from fish are used as hydroponic

nutrients.

• CO2 produced by the fish is absorbed by the

plants.

• Heat from the sun is converted with an air

source heat pump to store energy in the water

(25-28oC)

• Plant off-cuts are recycled in wormeries to

provide worms as feed for the fish.

Aquaculture - Fish Production. In the Greenhouse tilapia are grown as a food fish. Three tanks allow for fish to be grown from

stocking at 20-50g through to a harvest weight of around 500g, fish are continually harvested from

the system every week and are feed with a mixture of fish pellets and worms from the greenhouse’s

wormery. Tilapia are an omnivorous cichlid species from Africa but now widely cultured across the

globe. They are a fast growing and good quality white flesh fish and are also known as “fresh water

snapper” and the “aquatic chicken”.

The fish tanks have been designed with

windows to increases the interaction

with the stock and to help observe their

condition, behaviour and size.

The optimal temperature of range of 25

to 28oC also provides an efficient range

for heat storage.

Learning outcomes from the green-

house include fish physiology, fish be-

haviour, water quality, feeding and nu-

trition.

The The The GreenGreenGreenhousehousehouse

Information boards are placed around the

greenhouse outlining the basic principles of

aquaculture and also the parts of a fish (in this

case tilapia).

The Information boards are designed to remind

participants of the fishes requirements and also

the correct terminology.

Participants in the greenhouses are encouraged to

hand feed the fish as regularly as possible (little

and often) as physically seeing the fish respond to

feeding is a vital tool is understanding the health

and condition of the stock.

Tilapia can be cultured at up to 70kg/m3

however in an aquaponics system densities

of 20-30kg/m3 are more manageable.

Tilapia are mouth brooders and can easily

be breed, however for the growing of food

fish, male fish are favoured due to

increased growth rates and reduced inter

completion.


Hydroponics - Vegetable, Fruit & Flower Production.

Edible crops are grown on floating rafts in deep water circulation channels. The floating rafts suspend

the plants above flowing oxygenated nutrient rich water providing them with an ideal growing

environment, the rafts also act to insulate the body of water to prevent heat loss.

The crops themselves are grown in

plugs in a nursery system

Lettuce plugs are planted on the

floating rafts at day 21 from seed

and then grown on for a further 28

days before harvest.

This 6x9m greenhouse is designed to

produce around 72 lettuces per

week.

A range of crops can be grown from

fresh herbs to flowers, tomatoes,

peppers and salad crops.

Strawberries are also grown in the

Greenhouse in “strawberry towers”

where water trickles down vertical

planters filled with expanded clay

balls, the towers produce prolific

yields of fruit and provide a tasty

reward for those involved.

The greenhouse is capable of producing a wide variety of

crops ranging from salad crops, to herb, soft fruit,

flowers as well crops such as cucumbers, tomatoes and

peppers.

The Greenhouse is flexible in terms of the type of crops

that can be grown and their respective planting and

harvesting schedules, however it should be understood

that the plant and fish biomasses must be maintained in

balance.


Vermiculture: ”Wormeries” The recycling of plant off cuts and solid wastes from the filter tanks is a vital component of the

Greenhouse’s function. Wastes such as root material, uneaten food, and solid wastes are added to

wormeries to produce two valuable outputs.

1. Live worms .

Worms either for use as a

supplementary fish food, or for sale

as fishing bait.

2. Worm Tea

Made from the worm castings, worm

tea provides both a foliar plant feed

as well as a bio pesticide.

Vermiculture provides a valuable and

fun addition to the greenhouse system

and provides yet another visible link

between wastes and valuable resources

and most importantly reduces inputs to

and outputs from, the Greenhouse.

IPM - closing the loop The goal with aquaponics is to establish a natural balance of both predators and pests. Pesticides

are not used, however a range of complementary techniques are used including beneficial insects,

sticky traps and non toxic barrier treatments such as soap sprays.

As a further adoption of the ecosystem approach to growing food, we have stocked giant fresh

water prawns into the water of the hydroponic tanks to help clear up any solid wastes, algae and to

act as an additional food output, as well as freshwater mussels into the filter tank to absorb fine

Filtration System The filtration system serves three purposes; firstly to removed faeces and

uneaten food (to wormeries), secondly to remove fine solids (freshwater

mussels), and thirdly to remove gases in the water such as carbon dioxide and

nitrogen.

The filtration system is gravity fed and as such requires

no energy inputs.

Water is directed through the filtration system via baffles

and screens ensuring that the hydroponic tanks receive water that is rich in dissolved nutrients and

well oxygenated. Requiring regular but simple maintenance the filtration system, allows for the

conversion of ammonia into nitrites and then nitrites into nitrates which are then available for

absorption by the plants.


At an air temperature of 20-30oC inside the

greenhouse the air source heat pump operates

at a coefficient of performance (COP) of over

4.2, meaning that for every 1kw of electricity

input, 4.2kw of heat is produced.

Heat is extracted from the air and the cooled air

is returned into the Greenhouse, whilst the

heated water transferred to the water via a flat

plate heat exchanger.

The air in the Greenhouse can be heated in the

air handling unit (AHU) which also provides the

ability to control the extent of air recirculation

through variable dampers on the intakes.

The Greenhouse’s energy system provides an

energy efficient solution to heating and cooling

to provide a consistent and year round climate

for consistent crop production.

Building Management System (BMS) The Greenhouse is governed by a Priva BMS

controls. The control system allows for the

systems operation to be optimised according to

the outside air temperatures,

The BMS system also functions as a data logging

device and when linked to broadband, provides

remote maintenance and diagnostics, as well as

data collection for nationwide research.

BMS software and controls designed by

Aquaponics UK & Thermotec Ecosystems and

built by Ecotech.

Heating and Cooling

The Greenhouse’s energy system was developed

by Thermotec Ecosystems Ltd in partnership with

Aquaponics UK.

The idea behind the system is to capture the

solar energy during the day, using and air source

heat pump, and storing the surplus energy (25-

28oC) into the water of the aquaponics system

for passive back extraction (28-25oC) during the

night time for energy efficient heating.

The air source heat pump is utilised to provide

heating, cooling, dehumidification, and

ventilation.


Is the Greenhouse right for my application? The Greenhouse is ideally suited for areas where the requirement for high value food production

exists alongside the need for hands on educational and training resources.

For example in schools, colleges and probationary service institutions where food cant be used

onsite whilst the system itself provides a valuable and interactive resource.

The Greenhouse is an adaptable system that can be tailored to meet your requirements either in

terms of space, fish, or plant production.

Economies of scale exist so once investing in climate control for year round production, scaling up

is relatively cost effective, providing expansion is still within the supply to high value niche

markets.

For advice on the applicability of the Greenhouse system for your need please don’t hesitate to

get in touch — [email protected]

‘

About Us: Aquaponics UK was formed to provide a much needed link between the research community and

proactive organisations and individuals that share a common goal in developing Aquaponics.

We are a social enterprise company, limited by public guarantee and operating as a not for profit

organisation reinvesting any profits into scholarships, training, research grants and development.

We maintain strong links with both academic institutions and also commercial and industrial

organisations. Aquaponics UK intends to bring together these partnerships in a socially

transparent framework for the benefit of all.

Contact Us:

For further information on the

Greenhouse please contact:

Aquaponics UK (Ltd)

Institute of Aquaculture

University of Stirling

Stirling, Scotland

FK9 4LA

[email protected] www.aquaponics.org.uk

Aquaponics UK Director Charlie Price with George Alagia

during the filming of “The Future of Food” on BBC2

Documents

Aquaponics Greenhouse