Aquaponic Training Workshop
should be viewed with a degree of
caution because of different domestic market dependencies. Nonetheless, when addressing economic
optimization, the three most important factors are: (1) sustainability considerations, which in the case
of aquaponics, are interrelated with
economic profits, since the reuse of
resources should cut costs for the
producer and for the customer; (2)
technical optimization of processes
(e.g., nutrient availability in different growth stages, nutrient recycling, etc.), and; (3) system components (e.g., design of the hydrological regime, P recycling unit, pH stabilizing reactors, etc.)
System Design Considerations:
Aquaponics system design and application can be considered a highly
multidisciplinary approach drawing
from environmental, mechanical
and civil engineering design concepts as well as aquatic and plant
related biology, biochemistry, and
biotechnology. System specific
measurements and control technologies also require knowledge of
subjects related to the field of com-
Aquaponica Research
Basil in Aquaponic System
puter science for automatic control
systems. This high level of complexity necessarily demands in-depth
knowledge and expertise of all involved fields.
The design of aquaponic systems
closely mirrors that of recirculating
aquaculture systems in general with
the addition of a hydroponic component and the possible elimination
of a separate biofilter and devices
(foam fractionators) for fine and
dissolved solids removal. Fine solids
and dissolved organic matter generally do not reach levels that require
foam fractionation in aquaponic
systems at the recommended design ratio. The essential elements of
an aquaponic system consist of a
fish rearing tank, a settle able and
suspended solids removal component, a biofilter, a hydroponic component and a sump.
Component Ratios:
Aquaponic systems are generally
designed to meet the size requirements for solids removal (for those
systems requiring solids removal)
and biofiltration (if a separate biofilter is used) for the amount of fish
Tilapia Fish in Aquaponic
System
Aquaponic Farmer
being kept. After the size requirements are calculated, it is prudent
to add excess capacity as a safety
margin. However, if a separate biofilter is used, the hydroponic component is the safety factor because
a significant amount of ammonia
uptake and nitrification will occur
regardless of hydroponic technique.
Another key design criterion is the
ratio between the fish rearing and
hydroponic components. The key
aspect of the criterion is the ratio of
daily feed input to plant growing
area. If the ratio of daily feeding
rate to plant growing area is too
high, nutrient salts will accumulate
rapidly and may reach phytotoxic
levels. Higher water exchange rates
will be required to prevent excessive
nutrient build-up. If the ratio of daily feeding rate to plants is too low,
plants will develop nutrient deficiencies and more nutrient supplementation will be required.
The optimum ratio of daily fish feed
input to plant growing area will
max imize plant production while
maintaining relatively stable levels
of dissolved nutrients. A volume
NFT System