2/19/2018 Aquaponics Basics Hye-Ji Kim Assistant Professor of Sustainable Horticulture Crop Production February 13, 2018 Purdue University is an equal access/equal opportunity institution. “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)” Purdue University is an equal access/equal opportunity institution. 1 2/19/2018 Problems with Each System Aquaculture Hydroponics + Tilapia in an aquaculture tank . Rearing‐tank water has to be discharged . Commercial fertilizers are expensive at 10‐20% of total volume per day. Solution has to be replaced periodically . The discharged water becomes a . Disposal/runoff is problematic pollutant. 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 Purdue University is an equal access/equal opportunity institution. Source: Aquaponics: a brief history Source: http://m.zhongzi.net/en/news/1719.htm https://www.milkwood.net/2014/01/20/aquaponics‐a‐brief‐history/ Green Sky Growers, FL UVI aquponic system Mari’s Gardens, HI Urban Organics, MN Purdue University is an equal access/equal opportunity institution. Source: http://www.pentair.com 2 2/19/2018 ① Fish are fed fish meal and produce ammonia rich waste. Too much ammonia is toxic for the ② fish, but they can withstand high levels of nitrates. Biofilter ② The nitrifying bacteria breaks ③ Grow bed down ammonia into nitrites and then nitrates. Plants take in the converted nitrate as nutrients. ④ ③ Plants take in the converted ① Fish tank nitrate as nutrients. Through this ⑤ Air pump action, the plants purify water for the fish. Water ④ Oxygen enters the system pump Sediment through an air pump. This oxygen tank is essential for plant growth and fish survival. Schematic diagram of an aquaponics system ⑤ Water moves around the system by the action of water pump. Purdue University is an equal access/equal opportunity institution. Aquaponics Basics Types of Aquaponics Closed System: Recirculating or Coupled System Open System: Drain to Waste or Decoupled System Purdue University is an equal access/equal opportunity institution. 3 2/19/2018 Types of Aquaponics: Water vs. Substrate-base Water base: Substrate-base: Closed (Recirculating) System Open (Drain to Waste) System Gravels, Coco Coir Croutons Deep water culture “Raft” system Clay‐balls Lava‐rocks Nutrient Film Techniques (NFT) Drip irrigation Purdue University is an equal access/equal opportunity institution. 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. Purdue University is an equal access/equal opportunity institution. 4 2/19/2018 Aquaponics Basics Types of Aquaponics Components of Aquaponics • Plants • Growing Media • Fish • Microbes Purdue University is an equal access/equal opportunity institution. Plants do well in aquaponics Purdue University is an equal access/equal opportunity institution. 5 2/19/2018 Plants do well in aquaponics Fruit vegetables Leafy vegetables Purdue University is an equal access/equal opportunity institution. 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) • Substrate‐based system • NFT system • High‐nutrients‐requirements • Substrate‐based system Purdue University is an equal access/equal opportunity institution. 6 2/19/2018 Fish for Aquaponics Tilapia 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 23-27 13-18 24-30 23-27 18-24 18-24 23-27 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 9- 12 months 12-18 15-18 3 yrs 3 yrs 4 yrs reach maturity 12months months months Oxygen low high low low low low low requirement Purdue University is an equal access/equal opportunity institution. Adapted from Aquaponic Gardening (2011). Types of Growing Media Substrate choice for hydroponic seedling production . Good physical contact with seeds Source: http://www.wheatgrasskits.com/product/PP Substrate mixture Oasis Horticubes Peat pellets Substrates Synthetic media Organic Mineral (plugs, cubes, and blocks) components components Conventional peat moss perlite • polymer bound plugs (e.g. peat hydroponics coco coir Vermiculite pellets, coir pellets, composted organic sand Clay pebbles material plugs, Oasis Horticubes, sawdust urethane foam plugs) rice hulls • Rockwool cubes & blocks Purdue University is an equal access/equal opportunity institution. • coco coir cubes and blocks 7 2/19/2018 Aquaponics Basics Types of Aquaponics Components of Aquaponics Aquaponics Management • Water Quality • Nutrients • Other Considerations Purdue University is an equal access/equal opportunity institution. Aquaponics Management: Water Quality . Water source . TAN (Total Ammonia Nitrogen) ‐ . Temperature . Nitrite (NO2 ) ‐ . pH . Nitrate (NO3 ) . DO (Dissolved oxygen) Purdue University is an equal access/equal opportunity institution. TAN Nitrite Nitrate 8 2/19/2018 Aquaponics Management: Water Quality The pH Plants Microbes Purdue University is an equal access/equal opportunity institution. Fish Aquaponics Management: Water Quality Water Quality for Three Organisms The ideal compromise for aquaponics is necessary for the key water quality parameters. General Water Quality Parameters for Individual Organism Organism Type Temperature pH Ammonium Nitrite Nitrate DO (°C) (mg/L) (mg/L) (mg/L) (mg/L) Warm‐season 24‐30 Plants 5.5‐6.5 < 30 < 1 ‐ > 3 Cool‐season 10‐24 Warm‐water 22‐32 6‐8.5 < 3 < 1 < 400 4‐6 Fish Cold‐water 10‐18 6‐8.5 < 1 < 0.1 < 400 6‐8 Microbes 25‐30 7.3‐8.0 < 3 < 3 ‐ 4‐8 Ideal Water Quality Parameters for Aquaponics Aquaponics 20‐30 7 < 1 < 1 5‐150 > 5 Adapted from Small‐scale aquaponic food production. FAO (2014). Purdue University is an equal access/equal opportunity institution. 9 2/19/2018 Aquaponics Management: Nutrient Management Nutrient management ~45 essential nutrients protein (amino acids), fats (fatty acids), minerals, and vitamins Fish feed ① Fish ‐ Nitrite (NO2 ) Macronutrients: N,P,K , Ca,S,Mg ‐ Micronutrients: NO3 B, Cl, Mn, Fe, Zn, Cu, Mo ③ Plant ② Microbes Energy source Purdue University is an equal access/equal opportunity institution. Aquaponics Management: Nutrient Management Nutrient management Are fish diets formulated to meet the nutrient requirements for all 3 taxa? Purdue University is an equal access/equal opportunity institution. 10 2/19/2018 Aquaponics Management: Nutrient Management Nutrient management Fish diets were not formulated to meet the nutrient requirements for all 3 taxa. Feeding rate ~45 essential nutrients Feeding frequency Feeding time protein (amino acids), fats (fatty acids), minerals, and vitamins Fish feed ① Fish ‐ Nitrite (NO2 ) NO ‐ Macronutrients: 3 Energy source N,P,K , Ca,S,Mg ③ Plant ② Microbes Micronutrients: B, Cl, Mn, Fe, Zn, Cu, Mo Purdue University is an equal access/equal opportunity institution. Water Chemistry in Aquaponics Nitrification Fish feed Fish Solid waste ① Nitrosomonas Organic N + • 55 5 2 76 2 →572 − + 54 52 2 109 ‐ Nitrification NO2 ‐ ② Nitrobacter NO3 − + • 400 5 24 195 2 − + Denitrification 2 2→572 4003 Plant Microbes Nutrient uptake N2, NO, or N2O + ‐ (NH4 , NO3 ) Nitrogen flow (blue arrows) and potential loss (red arrows) in an aquaponics system. Photo: Stan Watson, Woods Hole Oceanographic Institut, 2010e: Purdue University is an equal access/equal opportunity institution. Photo: W.J.Hickey, University of Wisconsin, Madison, 2006 11 2/19/2018 Water quality parameters as affected by plant species 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 Purdue University is an equal access/equal opportunity institution. 8 2500 6 2000 1500 pH 4 1000 Aquaponics EC (µS/cm) 2 500 0 0 0 7 14 21 28 35 42 49 56 63 70 77 84 8 Days after Ttransplant 2500 6 2000 1500 4 *The pH was adjusted with a mixture of pH 1000 KOH and Ca(OH)2 in both systems. 2 EC (µS/cm) Hydroponics Lettuce Basil Tomato 500 0 0 0 7 14 21 28 35 42 49 56 63 70 77 84 Days after Transplant Electrical conductivity (EC) dynamically changes in aquaponics. Purdue University is an equal access/equal opportunity institution. 12 2/19/2018 Comparisons of aquaponics and hydroponics in yield and nutrient use Efficiency Plant crop Production Yield (g FW) / 3 months N use efficiency system (%) Marketable Unmarketable Plant Plant Part Parts + fish Aquaponics 152 a 868 b 512 a 13.5 18.6 Tomato Hydroponics 115 a 1661 a 338 a 14 14.0 Aquaponics 233 b – 124 b 2.5 7.0 Basil Hydroponics 287 a – 170 a 4.3 4.3 Aquaponics 121 b – 24 b 1.3 5.8 Lettuce Hydroponics 197 a – 31 a 3.0 3.0 Purdue University is an equal access/equal opportunity institution.