Aquaponics Basics February 13, 2018 Hye-Ji Kim Basics...• Proper aquaponics design is necessary for optimal crop yield. • Suitable fish/plants/fish feed combinations for high profitability

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Aquaponics Basics

February 13, 2018

Hye-Ji Kim

Assistant Professor of Sustainable Horticulture Crop Production


“Aquaponics” The Future Farming System

Aquaponics is a sustainable food production system that combineshydroponics with aquaculture in a symbiotic environment.

Aquaculture Hydroponics

+

Aquaponics is a major form of “organic hydroponics (bioponics)”

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Problems with Each System

Rearing‐tank water has to be discharged at 10‐20% of total volume per day. The discharged water becomes a pollutant.

Commercial fertilizers are expensive Solution has to be replaced periodically Disposal/runoff is problematic Nutrient concentration, pH, EC all have

to be monitored, adjusted, controlled. Recirculating systems prone to disease.

Tilapia in an aquaculture tank

Aquaculture Hydroponics

+

Water quality management is a challenge. Fish feeds are not designed for plants. Lack of scientific information


Source: http://m.zhongzi.net/en/news/1719.htmSource: Aquaponics: a brief history

https://www.milkwood.net/2014/01/20/aquaponics‐a‐brief‐history/

Mari’s Gardens, HIUVI aquponic system

Source: http://www.pentair.com

Urban Organics, MN

Green Sky Growers, FL

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Air pump

Water pump

Grow bed

Fish tank

Sediment tank

Biofilter

Schematic diagram of an aquaponics system

①

③

②

④

⑤

① Fish are fed fish meal andproduce ammonia rich waste. Toomuch ammonia is toxic for thefish, but they can withstand highlevels of nitrates.

② The nitrifying bacteria breaksdown ammonia into nitrites andthen nitrates. Plants take in theconverted nitrate as nutrients.

③ Plants take in the convertednitrate as nutrients. Through thisaction, the plants purify water forthe fish.

④ Oxygen enters the systemthrough an air pump. This oxygenis essential for plant growth andfish survival.

⑤Water moves around the systemby the action of water pump.


Aquaponics Basics

Types of Aquaponics

Closed System: Recirculating or Coupled System Open System: Drain to Waste or Decoupled System

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Nutrient Film Techniques (NFT)Nutrient Film Techniques (NFT)

Substrate-base: Open (Drain to Waste) System

Water base: Closed (Recirculating) System

Types of Aquaponics: Water vs. Substrate-base

Drip irrigationDrip irrigation

Gravels, Coco Coir CroutonsGravels, Coco Coir Croutons

Clay‐ballsClay‐balls

Lava‐rocksLava‐rocks

Deep water culture “Raft” systemDeep water culture “Raft” system


Closed (Recirculating) system

Types of Hydroponics: Open vs. Closed

Closed systems use 20–40% less water and fertilizer than open systems Consistent monitoring and maintenance of electrical conductivity (EC) and pH is required.

e.g. deep water culture, NFT, aeroponics

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Aquaponics Basics

Components of Aquaponics• Plants• Fish• Microbes

Types of Aquaponics

• Growing Media


Plants do well in aquaponics

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Plants do well in aquaponics

Leafy vegetables

Fruit vegetables

Root vegetables


Plants for AquaponicsLeafy

vegetablesFruit vegetables Root vegetables Flowers

Arugula Parsley Beans Beets Broccoli

Basil Spinach Cucumbers Carrots Cauliflower

Cabbage Swiss chard Eggplant Onions

Chive Watercress Okra Radishes Edible flowers

Kale Peas Ornamentals

Leek Amaranth Peppers

Lettuce Chia Strawberries

Mint Microgreens Squash

Mizuna Tomato

Mustard greens

Pak choi

• Deep water system (DWS)• NFT system• Substrate‐based system

• Substrate‐based system• High‐nutrients‐requirements

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Fish for AquaponicsTilapia Trout Catfish Bass Goldfish Koi Pacu

Edible yes yes yes yes no no maybe

Temperature (C) 16-35 2-20 2-32 4-32 2-32 2-32 16-35

Optimal Temperature (C)

23-27 13-18 24-30 23-27 18-24 18-24 23-27

Carnivorous or omnivorous

omnivorous carnivorous omnivorous carnivorous omnivorous omnivorous omnivorous

Mature size 1.5lb 0.8 lb 1.25 lb 1-3 lb 4” 20 lb 60 lb

Duration to reach maturity

9-12months

12 months 12-18 months

15-18 months

3 yrs 3 yrs 4 yrs

Oxygenrequirement

low high low low low low low

Adapted from Aquaponic Gardening (2011).


Substrate choice for hydroponic seedling production

Substrates Synthetic media(plugs, cubes, and blocks)Organic

componentsMineral

componentsConventional hydroponics

peat mosscoco coirsandsawdustrice hulls

perliteVermiculiteClay pebbles

• polymer bound plugs (e.g. peat pellets, coir pellets, composted organic material plugs, Oasis Horticubes, urethane foam plugs)

• Rockwool cubes & blocks• coco coir cubes and blocks

Types of Growing Media

Good physical contact with seeds

Source: http://www.wheatgrasskits.com/product/PPPeat pelletsOasis HorticubesSubstrate mixture

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Types of AquaponicsComponents of AquaponicsAquaponics Management

• Water Quality• Nutrients• Other Considerations

Aquaponics Basics


Aquaponics Management: Water Quality

NitrateTAN Nitrite

Water source Temperature pH DO (Dissolved oxygen)

TAN (Total Ammonia Nitrogen) Nitrite (NO2

‐) Nitrate (NO3

‐)

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Plants

Fish

Microbes

Aquaponics Management: Water QualityThe pH


The ideal compromise for aquaponics is necessary for the key water quality parameters.

Aquaponics Management: Water Quality

Adapted from Small‐scale aquaponic food production. FAO (2014).

General Water Quality Parameters for Individual Organism

Organism Type Temperature (°C)

pH Ammonium (mg/L)

Nitrite (mg/L)

Nitrate (mg/L)

DO (mg/L)

PlantsWarm‐season

Cool‐season

FishWarm‐water

Cold‐water

Microbes

Ideal Water Quality Parameters for Aquaponics

Aquaponics 20‐30 7 < 1 < 1 5‐150 > 5

24‐305.5‐6.5 < 30 < 1 ‐ > 3

10‐24

22‐32 6‐8.5 < 3 < 1 < 400 4‐6

10‐18 6‐8.5 < 1 < 0.1 < 400 6‐8

25‐30 7.3‐8.0 < 3 < 3 ‐ 4‐8

Water Quality for Three Organisms

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Fish feed Fish

Plant Microbes

Nitrite (NO2‐)

NO3‐

①

②③

~45 essential nutrientsprotein (amino acids), fats (fatty acids), minerals, and vitamins

Macronutrients:N, P, K , Ca, S, MgMicronutrients:B, Cl, Mn, Fe, Zn, Cu, Mo Energy source

Nutrient management

Aquaponics Management: Nutrient Management


Nutrient management


Are fish diets formulated to meet the nutrient requirements for all 3 taxa?

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Fish feed Fish

Plant Microbes

Nitrite (NO2‐)

NO3‐

①

②③

~45 essential nutrientsprotein (amino acids), fats (fatty acids), minerals, and vitamins

Macronutrients:N, P, K , Ca, S, MgMicronutrients:B, Cl, Mn, Fe, Zn, Cu, Mo

Energy source

Nutrient management


Fish diets were not formulated to meet the nutrient requirements for all 3 taxa.Feeding rateFeeding frequencyFeeding time


Nitrobacter

• 400 − 5 2 4+ 195 2

2 2 → 5 7 2 400 3− +

Nitrosomonas

• 55 + 5 2 76 2 → 5 7 254 − 52 2 109 +

Photo: Stan Watson, Woods Hole Oceanographic Institut, 2010e:

Photo: W.J.Hickey, University of Wisconsin, Madison, 2006

①

②

Water Chemistry in Aquaponics

Fish

Plant MicrobesN2, NO, or N2O

Denitrification

Fish feed

Nitrification NO2‐

NO3‐

Nutrient uptake (NH4

+, NO3‐)

Solid wasteOrganic N

Nitrogen flow (blue arrows) and potential loss (redarrows) in an aquaponics system.

Nitrification

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Parameter Tomato Basil Lettuce

TAN* (mg/L) 3.5±0.4 3.4±0.4 3.4±0.4 ns

Nitrite (mg/L) 3.8±1.5 3.8±1.5 2.5±0.9 ns

Nitrate (mg/L) 60.5±4.6 108.0±7.6 161.6±13.2 ***

Phosphate (mg/L) 22.6±0.6 23.3±1.0 21.8±0.5 ns

DO (mg/L) 6.7±0.1 6.5±0.1 6.7±0.1 ns

Temperature (°C) 26.3±0.2 25.9±0.2 26.1±0.2 ns

pH 6.8±0.1 6.7±0.1 6.7±0.1 ns

EC 523±18 832±43 912±52 ***

*Total ammonia nitrogen

Water quality parameters as affected by plant species


0

500

1000

1500

2000

2500

0

2

4

6

8

0 7 14 21 28 35 42 49 56 63 70 77 84

EC (µS/cm

)

pH

Days after Ttransplant

Aquaponics

Electrical conductivity (EC) dynamically changes in aquaponics.

0

500

1000

1500

2000

2500

0

2

4

6

8

0 7 14 21 28 35 42 49 56 63 70 77 84

EC (µS/cm

)

pH

Days after Transplant

Hydroponics Lettuce Basil Tomato

*The pH was adjusted with a mixture of KOH and Ca(OH)2 in both systems.

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Plant crop Production system

Yield (g FW) / 3 months N use efficiency (%)

MarketablePart

UnmarketableParts

Plant Plant + fish

TomatoAquaponics 152 a 868 b 512 a 13.5 18.6

Hydroponics 115 a 1661 a 338 a 14 14.0

BasilAquaponics 233 b – 124 b 2.5 7.0

Hydroponics 287 a – 170 a 4.3 4.3

LettuceAquaponics 121 b – 24 b 1.3 5.8

Hydroponics 197 a – 31 a 3.0 3.0

Comparisons of aquaponics and hydroponics in yield and nutrient use Efficiency


• Aquaponics facility structure and layout

• Lighting

• Cooling and heating

• Aquaponics pest control

• Processing and marketing

Other Considerations

Source: Ceres Greenhouse Solutions

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Major Challenges of Aquaponics• Knowledge of fish, bacteria, and plant production is essential to be

successful.• Daily management (e.g. water quality management) is mandatory.• Aquaponics alone will not provide a complete diet (nutrient

management).• Fish and plant requirements do not always match perfectly.• Reduced management choices compared with stand‐alone aquaculture or

hydroponic systems.• Energy demanding: requires reliable access to electricity

• Expensive initial start‐up costs compared with soil or hydroponicsvegetable production


Economic Feasibility of Aquaponics

Case Study : Purdue University (Temperate climate)

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Economic analysis results from Purdue University:

“Commercial scale aquaponics is economically feasible, only if

aquaponics produce are sold as organic produce from the third year of aquaponic business”

Vegetable production is the major driving force of economic success.

Fish production of tilapia in aquaponics is currently not profitable. High‐value fish should be introduced in aquaponics.

Case Study:


Economic Analysis of Aquaponics and Hydroponics Operation

Operating revenue and costs for aquaponics Operating revenue and costs for hydroponics

Flores, R.M.V., H.J. Kim, and K. Quagrainie. 2017. Economic analysis of aquaponics production in the US Midwest. Journal of Applied Aquaculture.

Case Study 2:

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• Aquaponics has great potential to be a future farming system.

• Aquaponics provides wellness tourism opportunity.

• Aquaponics provides unique educational opportunity to nurture for future farmers.

• Aquaponics can be profitable, if… • you are equipped with knowledge.

• your vegetables are sold as organic produce.

• you have local government support.

• Challenges need to be addressed: • Scientific research is needed to be done for successful operation

of aquaponics system with higher productivity and profitability.

• Proper aquaponics design is necessary for optimal crop yield.

• Suitable fish/plants/fish feed combinations for high profitability.


Kim’s Lab Current Lab membersTeng YangMeng‐Yang LinSeunghyun ChoiYi‐Ju WangSujoung ShimHuijia LiuZilong Ye

Undergrad ResearchersJeffrey BatesBrittany WeertsGaotian ZhuYoussef KaramBrandon HornHye Su LeeMitchell Ankney

Questions?

At HLA Fall Fling, Purdue Meigs Farm

Email at [email protected]

Documents

Aquaponics Basics February 13, 2018 Hye-Ji Kim Basics...• Proper aquaponics design is necessary for optimal crop yield. • Suitable fish/plants/fish feed combinations for high profitability