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Notes on aquaponics

02 Feb 2019

How aquaponics works (in a tiny nutshell)

  • fish effluence → clarifier/settler for anaerobic mineralization → biofilter for nitrification (aerobic NH3 + H2O → NO2 → NO3) → grow bed → sump → rearing tank
  • 0.5–1 lb fish ←→1 gal water ←→0.5–1 sqft grow bed
  • recirculating/closed-loop/media culture aquaponics vs. nutrient film technique vs. deep-water raft aquaponics
  • system inputs: fish feed, iron, magnesium

Notes from Aquaponic Gardening by Sylvia Bernstein

  • The Aquaponic Gardening Community
  • “Much of the greenhouse tomato, basil and lettuce production in North America today is done using hydroponic growing techniques…”

Lighting

  • needs to cover blue/red spectrum
  • fluorescent lighting with T5 bulbs
    • broad plant lighting spectrum
    • low power consumers, low heat
    • only reach through 18in (45cm) of plant canopy
    • need to replace every 6mo
  • high-intensity discharge (HID) lighting
    • metal halide (MH) for vegetative growth or high-pressure sodium (HPS) for mature/productive stage of fruiting plant
  • LED lighting
    • no heat, very low power consumption -> never replace bulbs
  • asdf

Grow beds and fish tanks

  • media bed better than NFT or deep-water culture (raft/DWC)
  • basic flood and drain: simplest design, for 1:1 grow bed to fish tank volume
  • add sump tank (CHIFT PIST/CHOP)
  • CHOP2: along with CHOP, allows 2-3:1 grow bed to fish tank ratio
  • Barrel-ponics
  • hybrid system
  • grow bed
    • industry standard >= 12in (30cm) deep for plant roots and complete filtration
    • media guard
  • fish tank

    • = 250gal (1000L) better for stability

    • need >= 50gal (200L) to raise fish to plate size, 12in (30cm)

Plumbing

  • pump
    • flow rate
    • head pressure, lift
  • pipes
    • usually polyvinyl chloride (PVC) or chlorinated polyvinyl chloride (CPVC)
    • half-inch (12mm) inner diameter PVC
    • alt to PVC: high-density polyethylene (HDPE)
  • pipe attachment
    • marine-grade silicone
    • Uniseals
    • bulkhead fitting
  • pump timer
    • mechanical or electronic timer
    • no-timer systems include autosiphons, flush valve systems
    • flood once per hour (15min on, 45min off)
    • flow entire folume of fish tank throw grow bed(s) every hour; e.g. 100gal tank with 15min on/hr needs a 400gph (gallon-per-hour) pump
  • Construction of automatic bell siphons

Grow media

  • 3 filtering functions
    • mechanical solid removal
    • mineralizzation (solids breakdown, return to water)
    • biofiltration
  • grow media purposes
    • structural
    • biofilter for solid waste
    • home for worms
    • air/water exchange
    • temperature moderation
  • media
    • cannot change water pH
    • cannot decompose
    • 12-18mm in diameter
    • should be porous
    • lightweight expanded clay aggregate (LECA/Hydroton), lava rock, expanded shale, gravel
  • gravel weighs 105lb/ft3 (1682kg/m3)

Water

  • water weighs 8lb/gal (1kg/L)
  • municipal water supply usually contains chlorine or chloramines, must be off-gassed
  • heating
    • aquarium heater
    • swimming pool heater for large tank; e.g. with titanium heating element
    • hydronic, radiant, or “in-floor” heating
  • dissolved oxygen
    • break surface tension of fish tank
    • aeration device for supplemental oxygenation
    • must be >3ppm, preferably >6ppm
  • pH
    • API Freshwater Master Test Kit (weekly) or digital pH meter
    • pH buffering agent
    • to raise pH: calcium hydroxide (hydrated lime), calcium carbonate (agricultural lime) with potassium carbonate, bicarbonate, potassium hydroxide (pearlash/potash)
    • to lower pH: hydroponic acids (nitric, phosphoric), vinegar; do not use citric acid
    • fish 6.5 - 8.0, plants 5.0 - 7.0, red words and bacteria 6.0 - 8.0
    • must be 6.4 - 7.6, optimally 6.8-7.0
    • tends to rise during cycling

Fish

  • 1lb (500g) fish for every 5-10gal (20-40L) for home media-based system
  • tilapia, goldfish, catfish, koi
  • shrimp, barramundi, pacu, perch, trout, oscars, freshwater lobster
  • keep temperature within 2C in 24hr period
  • feed 5min worth of food every hour
  • adult fish eat 1% of body weight per day, juvenile 7%
  • homegrown feed
    • duckweed
    • earthworms, sludge worms, bloodworms, composting red worms (red wrigglers)
    • black soldier fly larvae (BSF); check out BioPod

Plants

  • cannot grow plants that prefer too acidic or basic
    • acidic soil: blueberries azaleas
    • basic soil: chrysanthemums, calendula, zinnias
  • oxygen, hydrogen, carbon from air (O2, CO2) and water (H2O)
  • macronutrients: calcium, nitrogen, magnesium, phosphorus, potassium, sulfur
  • micronutrients: boron, copper, iron, manganese, molybdenum, zinc, aluminum
  • plant temperature depends on water temperature

Bacteria and worms

  • nitrifying bacteria: nitrosomonas and nitrospira
    • aerobic autotrophs
    • efficient at converting ammonica and nitrites
  • nitrosomonas convert ammonia to nitrites
  • nitrospira convert nitrites to nitrates
  • nitrosomonas NH4+ + 1.5O2 -> NO2- + 2H+ + H2O + 84kcal/mol of ammonia
  • nitrospira NO2- + 0.5O2 -> NO3- + 17.8 kcal/mol of nitrite
  • overall NH4+ + 2O2 -> NO3- + 2H+ + H2O + energy
  • optimal temperature 77-86F (25-30C)
  • maintain pH 6.0 - 8.5; nitrosomonas optimal 7.8 - 8.0, nitrospira 7.3-7.5
  • composting red worms for solid waste
    • worm castings or vermicompost

TODO

  • Cycling
  • System maintenance
  • Appendices

Good intros

More readings

  • Aquaponic Gardening: A Step-By-Step Guide to Raising Vegetables and Fish Together by Sylvia Bernstein
  • Aquaponics by Williams Walsworth
  • The Spotless Garden

Forums and threads

Sensors

Random notes

  • tilapia, perch, trout, hybrid striped bass, catfish, koi
  • shrimp, crayfish, shellfish
  • ducks, chickens, quail
  • bees
  • freshwater species
  • http://www.eatthis.com/10-superfoods-healthier-than-kale
  • https://en.wikipedia.org/wiki/Crop_tolerance_to_seawater

Insects

Businesses

Vertical farms

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