Hydroponics &
Aquaponics
An introduction to
alternative food
growing systems
Hydroponics
What is hydroponics?
• Growing plants in water, without soil
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Efficient
Fast growing
Crop density is high/limited space
Less pests, weeds, and soil borne diseases
Less physical labor
Less water than traditional farming
Hydroponics isn’t new
• 1627 book Sylva Sylvarum by Francis Bacon
• In 1699, John Woodward published his water
culture experiments with spearmint
• In 1937 William Frederick Gericke of the
University of California at Berkeley first coined
the term hydroponics
NASA Hydroponics
How does it work?
• Plants are suspended in a ph neutral medium
• Nutrient rich water is pumped through
allowing the plants to absorb what they need
• An air pump oxygenates the water for the
roots
• The water is recycled, until the nutrients are
nearly all absorbed by the plants and then
disposed of in a responsible way
Gravity fed hydroponics system
Nutrient rich water
Roots suspended
Pump pushes water
Air stone oxygenates
the water
In search of something else…
Aquaculture
Hydroponics
Why Search?
Recycling wastes into resources
Creating ecosystems
Combining the best of technologies
Promoting biodiversity
Producing food
Where can we use it?
Households – to enhance self sufficiency
Schools – to empower our next generation
Commercial production – more sustainable,
Communities – eliminate food oases and create resiliency
Urban Agriculture – fits perfectly in areas with population
density
Examples
The Plant – Chicago
From its beginnings as a 93,500 s.f. meatpacking facility, The Plant is being
repurposed into a net-zero energy vertical farm and food business
operation. A complex and highly interrelated system, one-third of The Plant
will hold aquaponic growing systems and the other two-thirds will incubate
sustainable food businesses by offering low rent, low energy costs, and
(eventually) a licensed shared kitchen.
Aquaponics – UK
Company took an abandoned building, fitted it with the most recent of
aquaponics technology and developed the Farm:shop. The system has now
been running for over a year and supplies a buzzing cafe with the sights,
sounds and smells of a living ecosystem as well as the freshest tilapia,
salad, herbs and soon shrimp…
Aquaponics
Why Aquaponics?
• Near zero environmental impact
• High quality hormone-free fish
• A level higher than organic vegetables
• No artificial fertilizers, pesticides, or herbicides
• 90% less water than conventional vegetable gardens
• 97% less water than standard aquaculture methods
• Versatile and adaptable
• Less waste than aquaculture and hydroponics
• Closed loop system
How does it work?
The Nitrogen Cycle
What can we grow?
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Tilapia (Oreochromis spp.)
Catfish (Ictalurus spp.)
Crappie (Pomoxis spp.)
Koi
Goldfish
Pacu
Trout
Barramundi (Australia)
Silver perch (Bairdiella sp.)
Golden perch (Macquaria sp.) (Australia)
Yellow perch (Perca flavescens)
Various ornamental tropical fish such as
guppies, tetras, swordtails, mollies, and
many others.
Freshwater prawns
Crayfish
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Green leaf, red leaf, and other leafy lettuces
Pak choi (bok choi)
Swiss chard
Arugula
Basil
Mint
Watercress
Chives
Mizuna and other micro-greens
Many common tropical plants / house plants
Deepwater, established systems
Tomatoes
Peppers
Cucumbers
Beans
Peas
Squash
3 primary forms of aquaponics
• Nutrient Film Technique (NFT)
• Grow Bed / Ebb and Flow
• Raft or Deep Water culture
Nutrient Film Technique (NFT)
Pros: plant roots are
exposed to a continuous
supply of water, oxygen,
and nutrients
Cons: less buffering
against interruptions in the
flow, e.g. power outages
Grow Bed/Ebb and Flow
1. Timer to cycle the pump,
which provides the ebb and
flow of nutrient dense
water and oxygen across
the plant roots
2. Use of a bell siphon or
loop siphon
Auto Siphons
Loop Siphon
Bell Siphon
Stand Pipe
Raft or Deep Water Culture
1. Most frequently used in
larger scale and commercial
scale aquaponics
2. Requires intensive
biological and mechanical
filtration to keep the water
clean and clear of any
solids waste
Filtration
• Biological
Aerobic bacteria convert the toxic
ammonia (NH3) produced by fish,
decomposing fish waste, uneaten
food, and dead plant matter into
nitrite (NO2) (also toxic) and then to
relatively non-toxic nitrate (NO3)
• Mechanical
removal of solids waste before broken down by
biological processes. This may be achieved by
passing the water through a fine material such as
a foam sponge, filter sock, or other synthetic
barrier, which traps the solids and is manually
removed and cleaned on a frequent basis. The
manual removal of organic solids benefits the
system by taking some of the demand off of
the biological filtration, reducing the amount of
oxygen used by bacteria in the mineralization
and nitrifying processes. This is important, as
your fish need that oxygen as well. If there is too
much solid waste in the system – uneaten food,
plant matter, etc., the dissolved oxygen may
drop to dangerously low levels.
Starting the Engine
The Murray Hallam Cycling Technique
1. Add liquid seaweed at a rate of 1 qt :
250 gal
2. Add plants
3. Wait for two weeks
4. Then add fish (low stocking density)
*Can add bacteria
*Can cycle without fish
*Can add synthetic ammonia
*Can add water from other systems
Starting the Engine
The Murray Hallam Cycling Technique
1. Add liquid seaweed at a rate of 1 qt : 250
gal
2. Add plants
3. Wait for two weeks
4. Then add fish (low stocking density)
*Can add bacteria
*Can cycle without fish
*Can add synthetic ammonia
*Can add water from other systems
Starting the Engine
The Murray Hallam Cycling Technique
1. Add liquid seaweed at a rate of 1 qt : 250
gal
2. Add plants
3. Wait for two weeks
4. Then add fish (low stocking density)
*Can add bacteria
*Can cycle without fish
*Can add synthetic ammonia
*Can add water from other systems
Starting the Engine
The Murray Hallam Cycling Technique
1. Add liquid seaweed at a rate of 1 qt : 250
gal
2. Add plants
3. Wait for two weeks
4. Then add fish (low stocking density)
*Can add bacteria
*Can cycle without fish
*Can add synthetic ammonia
*Can add water from other systems
Blue Tilapia
Equipment
Basic Parts and Supplies
• Fish Tanks
• Grow Trays or NFT Channels
• Growing media
• Plumbing
• Biological Filter
• Mechanical Filter
• Water Pump
• Water Heater (if needed)
• Air pump / Diffusers
• Net Pots (for NFT)
• Lighting (if indoors)
Fish Tanks, Ponds & Barrels
A variety of containers can be used to hold your
fish. Aquariums, blue barrels, prefab ponds,
pond liners. I’ve seen horse troughs too.
You can also purchase pre-made systems from
many manufacturers.
Or you can build your very own….
Rat terrier not included
Grow Trays and NFT Channels
Specialty growing trays and NFT channels can be
purchased through hydroponic and agriculture
equipment companies. I’ve used plastic cement
mixing trays and plastic storage containers. For
NFT you can use rain gutter downspouts and
drop in growing pots.
Grow Media
Hydroton LECA (lightweight
expanded clay aggregate)
is a popular hydroponic
grow media. It’s inert,
reusable, and highly
porous, providing
extensive surface area for
biological filtration.
Lighting
The sun is the finest light source for aquaponics.
For growing indoors, however, there are a
number of artificial light options for indoor
gardening, including high output fluorescent,
metal halide, mercury vapor bulbs, LED, and
plasma lights.
Water Heaters
Air Pumps
Tilapia
• Third most important fish in aquaculture after
carps and salmonids.
• Good source of protein
• Reproduce fairly easily, every 4 weeks
• Can be grown as fry in aquariums
• Can be grown to plate size in 55 gal barrels
• Ratio of fish to water capacity is one pound of
fish for every five gallons of water
Feeding
• Feed fish as much as they will eat in 3-5 minutes, 3 times per day.
Allow four to five hours between feedings for optimal metabolism
• Take care not to overfeed fish.
• Provide a high-quality fish food of appropriate size – fingerlings will
take a much smaller pellet size than juvenile and adult fish.
• An adult tilapia will eat approximately 1% of its bodyweight per
day.
• Fish fry (babies) will eat as much as 7%.
• Fish that are not eating may be: stressed due to high ammonia
level; outside of their optimal temperature range; lacking sufficient
oxygen (discontinue feeding if dissolved oxygen drops below 3ppm)
Water Quality Basics
• pH of 7 is ideal
• Ammonia and nitrite levels should be less than .25 ppm.
• Oxygen
– Provide plenty of aeration in your fish tanks.
– Strong water flow improves oxygen saturation.
– Avoid overfeeding or overcrowding the fish.
– Fish gasping for air at the water surface is a sign they are lacking
oxygen.
Harvesting
• Tilapia are generally ready to harvest at 6-9 months of age, but the
growth rate is dependent upon feeding regimen and number of fish
in a system.
Water Sources
• Rainwater and clean well water
• Municipal water can often have chlorine and
chloramine added
• There are many water conditioners available,
be certain they are human safe
• Vitamin C
• R/O System
Now let’s have some fun!
• Please split into four groups
• Bring your water bottles
• We will be building a hydroponic system
What we are building