What is Aquaponics: Aquaponics is the growing of agricultural plants alongside aquatic animals in a circulatory system. The system combines hydroponic system with aquaculture in symbiotic environment.
Water from aquaculture is fed to hydroponic system where nitrified bacteria breaks down byproducts excretions into nitrites then further to nitrates. The plants in aquaponic use the nitrate nutrients to grow.
Ancient farming cultures offers an insight on similarities with modern aquaculture. We have 13th century rice farming using floating raft platter system and South China cultivation of rice in paddy fields combined with fish farming.
Commercial aquaponic system has good viability in fish and plant production. The system reduces the dependence on wild stock and is practicable in urban dwelling.
It is perfect for low cost vegetable/fish production, tourism and food sustainability. The system taught in correctional institutions, schools and tertiary institutions
Parts of aquaponic system
Aquaponic system is segmented into two parts hydroponic for plant production and aquaponic for aquatic creature production. The system operates a circulatory system resulting from uneaten food and concentration of effluence.
Subsystem components remove solid waste, ammonia buildup and adds oxygenated water, neutralizes acids. Typical components include bio filters, sump, hydroponics subsystems, rearing tanks and settling basing.
Components of aquaponic system
- bio filters
- hydroponics subsystems
- rearing tanks
- settling basing
Live components of Aquaponic system
Live components of aquaponic system are bacteria, aquatic creatures and plant. The most popular aquatic creature introduced into the system are fish. Most systems adapt freshwater culture however there are also saltwater systems.
Type of aquatic creatures in aquaponic
The type of fish are freshwater fish however other aquatic animals like prawn or crayfish work. Edible fish raised for commercial purpose or home consumption are mostly catfish or tilapia.
Common fish introduced in the system are rainbow trout, channel catfish, bluegill, jade perch and eel-tailed catfish. Others are silver perch, barramundi, Murray cod, koi, goldfish, striped bass, common carp and largemouth bass. Other aquatic creatures sometimes used are prawns or crayfish.
Fist type in the culture
- rainbow trout
- channel catfish
- jade perch
- eel-tailed catfish
- silver perch
- Murray cod
- striped bass
- common carp
- largemouth bass
Other aquatic creatures
Stocking density of fish the size of system and farmers requirement dictate the type of plant introduced in the system. Fish effluence concentration plays an important part in nutrients the plant root receives.
Popular vegetables to grow are lettuce, tomatoes, bell peppers, cabbage, basil and okra. More are watercress, capsicum, spinach, herbs, chives, cucumbers, peas, onions and shallots.
- Bell peppers
Difference between hydroponic and aquaponic
Hydroponic system involves immersion of plant roots in nutrient rich effluent water. The plant metabolizes or filter out toxic ammonia. Water passes through a hydroponic system is cleaned, oxygenated and returned to aquatic containers in a continuous cyclic movement.
Common aquaponic applications common to hydroponic are nutrient film technique and deep water rafting. Others are flood-and drain aquaponic system, recirculating.
Operational inputs involves oxygenation, fresh water and feed for aquatic creatures. Others are use of electricity, pumps, PVC light source, aeration and filtration. Therefore guide principles in a successful aquaponic system are control, bio-filtration, appropriate piping.
Others are biological pest control, control of aggregators, and removal of solids. More are appropriate aeration, feeding of animal life good feed conversion ratio.
What are the feed sources for aquatic life or plant nutrients?
Aquatic environment is maintained between relationship of plant and animals. While water added only to replace water loss. Energy depends on the type of technology used by the farmer.
Feed sources include organic fish feed, fish meal, live meal, duckweed, worms, kitchen waste, blackfly or grubs. Plant nutrients include minerals, micronutrients, introduction of potassium sulfate and high nitrate concentration from bio-filtration system.
The ratio of fish to plant life is carefully estimated for optimum results. To maximize output farmers leverage on three types of stocking methods. Stocking method of fish are use of multiple rearing units, sequential rearing and stock splitting method.
Multiple rearing unit involves the use of several tanks with shared filtration unit. There is predominantly a large rearing tank and smaller tanks. Once fish is harvested from large rearing tank. Then next set are moved to larger tank.
Stock splitting involves one large tank for the fish which is later split into two as the fishes grow. Sequential rearing is the most common type of stocking. The farmer stocks fish of same size and raise till adulthood then harvests. He later replaces them with fish of same size to start the process over again.