Aquaponics Basics. Hye-Ji Kim Assistant Professor of Sustainable Horticulture Crop Production. Aquaponics The Future Farming System

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1 Aquaponics Basics Hye-Ji Kim Assistant Professor of Sustainable Horticulture Crop Production February 13, 2018 Aquaponics The Future Farming System Aquaponics is a sustainable food production system that combines hydroponics with aquaculture in a symbiotic environment. Aquaculture Hydroponics + Aquaponics is a major form of organic hydroponics (bioponics) 1

2 Aquaculture Problems with Each System Hydroponics Tilapia in an aquaculture tank 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. Water quality management is a challenge. Fish feeds are not designed for plants. Lack of scientific information Source: Source: Aquaponics: a brief history a brief history/ Green Sky Growers, FL UVI aquponic system Mari s Gardens, HI Urban Organics, MN Source: 2

3 2 Biofilter Air pump Grow bed 1 Fish tank Water pump Sediment tank Schematic diagram of an aquaponics system 1 Fish are fed fish meal and produce ammonia rich waste. Too much ammonia is toxic for the fish, but they can withstand high levels of nitrates. 2 The nitrifying bacteria breaks down ammonia into nitrites and then nitrates. Plants take in the converted nitrate as nutrients. 3 Plants take in the converted nitrate as nutrients. Through this action, the plants purify water for the fish. 4 Oxygen enters the system through an air pump. This oxygen is essential for plant growth and fish survival. 5 Water moves around the system by the action of water pump. Aquaponics Basics Types of Aquaponics Closed System: Recirculating or Coupled System Open System: Drain to Waste or Decoupled System 3

4 Types of Aquaponics: Water vs. Substrate-base Water base: Closed (Recirculating) System Substrate-base: Open (Drain to Waste) System Gravels, Coco Coir Croutons Deep water culture Raft system Clay balls Lava rocks Nutrient Film Techniques (NFT) Drip irrigation Types of Hydroponics: Open vs. Closed Closed (Recirculating) system e.g. deep water culture, NFT, aeroponics Closed systems use 20 40% less water and fertilizer than open systems Consistent monitoring and maintenance of electrical conductivity (EC) and ph is required. 4

5 Aquaponics Basics Types of Aquaponics Components of Aquaponics Plants Fish Microbes Growing Media Plants do well in aquaponics 5

6 Plants do well in aquaponics Fruit vegetables Leafy vegetables Root vegetables Plants for Aquaponics Leafy Fruit vegetables Root vegetables Flowers vegetables 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 6

7 Fish for Aquaponics Tilapia Trout Catfish Bass Goldfish Koi Pacu Edible yes yes yes yes no no maybe Temperature (C) Optimal Temperature (C) Carnivorous or omnivorous carnivorous omnivorous carnivorous omnivorous 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 months months 3 yrs 3 yrs 4 yrs Oxygen requirement low high low low low low low Adapted from Aquaponic Gardening (2011). Types of Growing Media Substrate choice for hydroponic seedling production Good physical contact with seeds Substrate mixture Oasis Horticubes Substrates Organic Mineral components components peat moss perlite coco coir Vermiculite sand Clay pebbles sawdust rice hulls Conventional hydroponics Source: Peat pellets Synthetic media (plugs, cubes, and blocks) 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 7

8 Aquaponics Basics Types of Aquaponics Components of Aquaponics Aquaponics Management Water Quality Nutrients Other Considerations Aquaponics Management: Water Quality Water source Temperature ph DO (Dissolved oxygen) TAN (Total Ammonia Nitrogen) Nitrite (NO 2 ) Nitrate (NO 3 ) TAN Nitrite Nitrate 8

9 Aquaponics Management: Water Quality The ph Plants Microbes Fish The ideal compromise for aquaponics is necessary for the key water quality parameters. Organism Type Aquaponics Management: Water Quality Water Quality for Three Organisms General Water Quality Parameters for Individual Organism Temperature ( C) ph Ammonium (mg/l) Nitrite (mg/l) Nitrate (mg/l) DO (mg/l) Plants Warm season Cool season < 30 < 1 > 3 Fish Warm water Cold water < 3 < 1 < < 1 < 0.1 < Microbes < 3 < Ideal Water Quality Parameters for Aquaponics Aquaponics < 1 < > 5 Adapted from Small scale aquaponic food production. FAO (2014). 9

10 Aquaponics Management: Nutrient Management Nutrient management Fish feed 1 Fish ~45 essential nutrients protein (amino acids), fats (fatty acids), minerals, and vitamins Nitrite (NO 2 ) Macronutrients: N,P,K, Ca,S,Mg Micronutrients: NO 3 B, Cl, Mn, Fe, Zn, Cu, Mo 3 Plant 2 Microbes Energy source Aquaponics Management: Nutrient Management Nutrient management Are fish diets formulated to meet the nutrient requirements for all 3 taxa? 10

11 Aquaponics Management: Nutrient Management Nutrient management Fish diets were not formulated to meet the nutrient requirements for all 3 taxa. Feeding rate Feeding frequency Feeding time Fish feed 1 Fish ~45 essential nutrients protein (amino acids), fats (fatty acids), minerals, and vitamins Nitrite (NO 2 ) Macronutrients: N,P,K, Ca,S,Mg Micronutrients: B, Cl, Mn, Fe, Zn, Cu, Mo 3 Plant NO 3 2 Microbes Energy source Water Chemistry in Aquaponics Nitrification Fish feed Fish Solid waste Organic N 1 Nitrosomonas Plant Nutrient uptake (NH 4+, NO 3 ) Nitrification NO 2 NO 3 Denitrification Microbes N 2, NO, or N 2 O 2 Nitrobacter Nitrogen flow (blue arrows) and potential loss (red arrows) in an aquaponics system. Photo: Stan Watson, Woods Hole Oceanographic Institut, 2010e: Photo: W.J.Hickey, University of Wisconsin, Madison,

12 Water quality parameters as affected by plant species Parameter Tomato Basil Lettuce TAN* (mg/l) 3.5± ± ±0.4 ns Nitrite (mg/l) 3.8± ± ±0.9 ns Nitrate (mg/l) 60.5± ± ±13.2 *** Phosphate (mg/l) 22.6± ± ±0.5 ns DO (mg/l) 6.7± ± ±0.1 ns Temperature ( C) 26.3± ± ±0.2 ns ph 6.8± ± ±0.1 ns EC 523±18 832±43 912±52 *** *Total ammonia nitrogen ph ph Aquaponics Days after Ttransplant *The ph was adjusted with a mixture of KOH and Ca(OH) 2 in both systems. Hydroponics Lettuce Basil Tomato Days after Transplant EC (µs/cm) EC (µs/cm) Electrical conductivity (EC) dynamically changes in aquaponics. 12

13 Comparisons of aquaponics and hydroponics in yield and nutrient use Efficiency Plant crop Production system Yield (g FW) / 3 months N use efficiency (%) Marketable Part Unmarketable Parts Plant Plant + fish Tomato Basil Lettuce Aquaponics 152 a 868 b 512 a Hydroponics 115 a 1661 a 338 a Aquaponics 233 b 124 b Hydroponics 287 a 170 a Aquaponics 121 b 24 b Hydroponics 197 a 31 a Other Considerations Aquaponics facility structure and layout Lighting Cooling and heating Aquaponics pest control Processing and marketing Source: Ceres Greenhouse Solutions 13

14 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 hydroponics vegetable production Economic Feasibility of Aquaponics Case Study : Purdue University (Temperate climate) 14

15 Case Study: 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 2: 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 Economic analysis of aquaponics production in the US Midwest. Journal of Applied Aquaculture. 15

16 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 members Teng Yang Meng Yang Lin Seunghyun Choi Yi Ju Wang Sujoung Shim Huijia Liu Zilong Ye Questions? at hyejikim@purdue.edu Undergrad Researchers Jeffrey Bates Brittany Weerts Gaotian Zhu Youssef Karam Brandon Horn Hye Su Lee Mitchell Ankney At HLA Fall Fling, Purdue Meigs Farm 16