Disclaimer: Please note and abide by copyright laws. Some items contained in these presentations are taken from copyrighted material without express permission of redistribution. These slides are archived here for your use in educational activities. Although an educational use exemption would apply these presentations are catalogued here for educational purposes only. Unit 2.2 System Components

Aquaponics System Components

System Components Individual components Not all components are used in all system designs Presentation titled System Designs will discuss Raft Flood and Drain Nutrient Film Technique (NFT)

FISH TANKS

Fish tanks Every system requires at least one, large systems have multiple Size and type of tank is dependent on intended use Small indoor system for educational use may use a plexi-glass aquarium Large outdoor commercial system may use large fiberglass or polyethylene tanks Tanks range from a few hundred to thousands of gallons Tank should be sturdy, durable and designed to hold the amount of water needed Must be food-grade plastics or materials Round tanks provide the best movement of water Water and fish tend to move in a circular motion – this also forces fish waste to center bottom of tank Square tanks allow for waste to collect in corners and create anaerobic zones Tanks with Conical bottom provide natural settling for fish waste

Stand pipes and bottom drains Sets water level Keeps fish from escaping from fish tanks through the bottom drain Directs the water with fish waste down the drain Not all systems use a stand pipe Bottom Drain Allows for water to leave the fish tank and move to the other components in the system

Stand pipes and bottom drains Commercial System Small System

AERATION SYSTEM Aeration is the process of adding oxygen to the system Fish, plants, and beneficial bacteria all need oxygen Aeration is also critical for biological filtration and off-gassing processes Air blower or compressor is used to supply air to air diffusers located in the system Air diffusers break the stream of air into micro bubbles Bubble size and depth at introduction directly affect the amount of aeration An air bubble rising from 5 feet provides more air than identically sized bubble rising from 3 feet

AIR BLOWER and DIFFUSERS Air Diffuser

Air Diffuser In the raft system there are air diffusers in the fish tank(s), the degassing tank and the raft tank(s) Placement should allow for easy removal Diffusers should be cleaned periodically Number of diffusers and oxygen flow rate is dependent on the size and design on the system

Solids Removal Device (Clarifiers) Required for raft and NFT Media-filled bed systems use the media as a solids removal device Removal of solid waste allows for Higher stocking density of fish More plant production Utilization of waste to fertilize soil in traditional farming There are several styles of clarifiers used in aquaponics - two of which are common Conical clarifier Settling basin

Conical Clarifier A : Water enters the clarifiers from the fish tank Water is slowed as it hits the baffle and flows downward under the baffle B : Solids drop to the bottom of the cone C : Clean water rises D : Clean water exits to move to other system components E : Solids are removed by opening of the valve

Settling Basin Flat tray that is only a few inches deep and a couple of feet long Dependent on size of the system Water enters one end and exits the other As the water enters the tray large solids settle to a deeper basin Bottom of basin has drain valve that is opened periodically to flush solids out As water moves finer solids settle Just before the exit end there is a weir (dam) that the water must flow over Most remaining solids drop behind the weir

Solids Removal One of the most important processes in recirculating raft and NFT Waste build-up: Leads to toxicities Clogs plumbing Coats plant roots Unable to uptake nutrients Design is dependent on the size and required rate of water flow of the system Flow rate must be quick enough to meet exchange requirements yet slow enough to allow solids to settle Turbulence in clarifier is unwanted as it will break down large solids into suspended solids that remain in the water

Biofiltration Tank Biofilter is a place for beneficial bacteria to colonize Large surface area Proper temperature Proper pH Proper dissolved oxygen Required in NFT because the channels do not provide enough surface area Not usually used in raft and flood and drain because rafts, media, tank walls, and all other surfaces generally provide enough area for bacteria to colonize

Biofiltration Tank Usually a canister, tank, or barrel that holds a porous media and is heavily aerated Water from fish tank runs through the biofilter where ammonia will be converted to nitrite then nitrate Essentially the whole aquaponics system is a biofilter

Mineralization tank Process by which heterotrophic bacteria convert solid waste into ammonia and other elements for the plants Used in raft and NFT designs Contains loose media that suspended solids collect on UVI mineralization tanks uses orchard netting Suspended solids collect on netting and the netting is then washed periodically As solids collect on netting anaerobic conditions occur and gasses are formed Hydrogen sulfide, methane, and nitrogen

Mineralization tank

Degassing tank Aerated tank that encourages the expulsion of gasses into the air Used in raft and NFT designs Tank that comes after the mineralization tank

Grow Bed Where plants are grown Hydroponic component Raft Media-filled NFT

Sump Tank and Water Pumps Sump tank is lowest point in system Water pump moves water from sump tank back to fish tanks Installation of two water pumps with a cross over valve is needed in the event the pump fails Size of pump is related to size of system Water is regulated by a float valve in the sump tank

Plumbing PVC connects the components of the aquaponics system Diameter of pipe is critical to flow rates Volume and velocity affect flow rate in pipes Too large of a diameter causes slow flow and solids begin to settle in pipes and create water quality issues Too small of a diameter may cause pipe to clog Installation of clean out plugs allow operator to clean the inside walls of pipes if they become clogged

Water Heater/Chiller Used to maintain proper water temperature Depends on species of fish and plants Consistent water temperature produces higher quality of crops In a greenhouse winter air temperature can remain cooler and summer air temperature can remain warmer as long as the root temperature is maintained Saves energy in the long run

Back Up Power Equipment Preparation for power outage or equipment failure Small system Battery back up Home food or commercial production Generator Have more than one water pump and air blower in case of mechanical failure Automated monitoring system System sends notification to operator via phone if greenhouse and environmental conditions are outside of set parameters and sends notification of power failure

Plant Lighting Increase lettuce and herb production in greenhouse setting by up to 40% Metal halide lights for lettuce and herbs Lights provide BTUs of heat which is beneficial in cold climates Saves energy More on lighting will be discussed later in the course

Greenhouse and Environmental Control Growing indoors when natural environment is not compatible with crops needs Additional equipment needed Air heaters Ventilation Cooling Humidification More about greenhouse and controlled environment will be discussed later in the course

REFERENCE Nelson, R. L. Aquaponic Food Production Raising Fish and Plants for Food and Profit. 2008. Nelson and Pade, Inc. Montello, WI. Pgs. 36-44. With contributions from John S. Pade