Aquaculture Research

1. This presentation was produced and is copyrighted by Stewart- Peterson®, Inc. 2003-2005.
Permission is granted for use by active AgEdNet.com® subscribers. All other use is prohibited.
STEWART-PETERSON and AGEDNET.COM are registered trademarks of Stewart-Peterson, Inc.
AC012 Combining
Aquaculture
with Hydroponics
Aquaculture Library

2. A natural pond setting …
• Fish, bacteria and plants all work together
to provide nutrients and dispose of waste.
• The ammonia/nitrogen cycle is key.

3. The ammonia/nitrogen cycle:
Nitrosomonas
Bacteria
Algae,
Plants
Fish Wastes,
Uneaten Feed
Nitrobacter
Bacteria
Ammonia (NH3)
Nitrate (NO3)
Nitrite (NO2)
Fish Feed

4. Here’s how it works …
• Fish live in their own bathroom.
• Fish waste is mostly ammonia.
• Excess feed also produces ammonia.
• Too much ammonia and all the fish are
dead.

5. Bacteria to the rescue …
• Certain bacteria LOVE ammonia.
• Nitrosomonas bacteria eat up the
ammonia and give off nitrite.
• But too much nitrite is also dangerous to
fish.

6. Now it’s more bacteria riding
to the rescue …
• Nitrobacter bacteria love nitrites.
• These bacteria give off nitrates as a waste
product.
• Once again, too many nitrates will kill the
fish.

7. Then it’s plants that step up
to the plate …
• The plants feed on the nitrates and grow
big and strong.
• Fish swim along and eat the plants,
releasing ammonia as waste and
• THE WHOLE CYCLE STARTS AGAIN!

8. What is aquaponics?
• A combination of aquaculture and
hydroponics
• Fish, plants and bacteria working together
to meet each others needs.
• Fish produce the ammonia
• Bacteria break down the ammonia to nitrates.
• Plants feed on the nitrates to produce fish
food.

9. Aquaponics is experimental:
• True recycling systems that reuse water
and nutrients
• No groundwater pollution
• No nutrient runoff
• Less than 1/10th the fertilizer and 1/100th
the water of traditional systems
• Outperforms traditional agriculture up to
30:1

10. More about aquaponics:
• It is a closed-loop
ecosystem.
• Combines growing
fish and plants
• A manmade version
of Mother Nature’s
pond, stream and
field ecosystem Photo courtesy K. Fitzsimmons.

11. A simple system:
• Fish in a fish tank
• Pump moves water from the tank through
a series of troughs on top of the tank
• Pots have plants in rockwool
• Fish wastes are trapped in the rockwool
and feed the plants
• Clean water flows from plants back to the
fish tank.

12. More elaborate systems:
• Systems to separate solid vs. dissolved
waste
• Automatic monitors, backup pumps
• Automatic fish feeding system
• System to maximize plant growth

13. Pretty great system, right?
• An aquaponic system is nearly a total
recycling program.
• Plants feed fish.
• Fish waste feeds
bacteria.
• Bacteria
feed plants.
• But fish grow,
so you need
to feed them.
Photo courtesy K. Fitzsimmons.

14. System requirements:
• Bacteria like temperatures of 75-80 F
• Bacteria are slow to adapt to changes, so
limit changes in feed volume.
• Too few fish? Fertilize the plants.
• In water – not approved for food grade fish
• Spray on the leaves (foliar)
• Don’t forget light for the plants.
• Avoid too much heat from the lights.

15. The ammonia/nitrate cycle
Nitrosomonas
Bacteria
Algae,
Plants
Fish Wastes,
Uneaten Feed
Nitrobacter
Bacteria
Ammonia (NH3)
Nitrate (NO3)
Nitrite (NO2)
Fish Feed

16. This presentation was produced and is copyrighted by Stewart- Peterson®, Inc. 2003-2005.
Permission is granted for use by active AgEdNet.com® subscribers. All other use is prohibited.
STEWART-PETERSON and AGEDNET.COM are registered trademarks of Stewart-Peterson, Inc.
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