Aquaponics
system facilitates simultaneous nurturing of plants and fish by
re-circulating water as well as the nutrients that are produced in
the system for the growth of the plants as well as the species that
are included in the system. This new method for simultaneous
management of farm and fish pond is gaining momentum the world over
since it provides a sustainable as well as cost-effective solution
for farming and growing fish simultaneously.
Various
types of warm-water and cold-water fish species can be raised using
this method. The fish species that are widely cultivated using this
method include perch, Arctic char, trout, bass, cod and tilapia.
Among
all the fish species tilapia is the most suited for cultivation in
aquaponics systems since the tilapia fish can withstand various
fluctuations in the aquatic conditions such as temperature, oxygen
content, dissolved substances and pH. Since tilapia fish has good
demand in the market, cultivation of this variety is highly
profitable also.
Plants
cultivation
Cultivation
of various plants is the other purpose of aquaponics system. Leafy
greens and various herbs are cultivated in this system. However, it
depends on the density of the fish tank and the nutrients that are
present in the fish waste. The plants that are grown in the system
absorb the nutrients that are present in the fish waste and the type
of nutrients in the fish waste depends on the type of fish species
that grow in the tank.
The
water from the fish tank is drained out and filtered and used for
irrigation of the plant. Since the fish waste is a rich source of
nitrogenous fertilizer it is ideal for raising the leafy plants. The
plants such as lettuce, spinach, watercress, basil and chives grow
very well in aquaponics systems since the nutritional needs of these
plants and herbs are very low.
Fruit-yielding
plants like tomato and cucumber also can be cultivated in aquaponics
systems. However, since the nutritional requirements of these plants
are higher, the system must be sufficiently stocked as well as
provided. Cucumbers and tomatoes grow healthy and give good yield in
aquaponics system, provided the plants are fed with sufficient
quantity of nutrition.
Filling
the pots with compost is the most effective method to provide all the
nutrients that are required by the plants. Root crops such as carrot
and potato can give the yield only if they are grown in soil. Hence
the aquaponics method of cultivation is not suitable to them.
Monitoring the water quality
The
success of an aquaponics system also depends on the condition of the
water that is used in the system. Fish, plants and water are the
vital components of this system. In order to ensure safe as well as
healthy environment for the fish that is grown in the system, the pH
of the water that is stored in the system is to be carefully
monitored. Since the fish as well as the plants in the systems are to
be kept healthy and growing, periodic checking of the quality of the
water using the right equipments is all the more important.
The
farmer should also monitor the levels of dissolved oxygen, ammonia,
carbon dioxide, chlorine, nitrates and nitrites in the water. The
quality of water undergoes rapid change with changes in the density
of fish in the tank, growth rate of the fish and the amount of feed
they are provided. The fish species, fish density, plant species and
other aspects determine the ratio of water in the fish tank to the
hydroponic products. However as a general rule, the ratio of tank
content to bed content will be 1:4.
Conversion of ammonia
Aquaponics
system can be provided with biofilters that facilitate natural
filtering out of the harmful substances from the water. When the
pollutants are filtered out completely, the process of conversion of
ammonia into nitrite and then to nitrate is made hassle-free.
In
some of the systems, the fish waste is directly added into the
system. The chemical process of conversion of toxic ammonia into
nitrites and then to nitrate is facilitated by the gravel bed of the
system. The gravel bed functions as a bioreactor and removes the
dissolved solids from the water thereby providing the space for the
nitrifying bacteria to get converted into nitrogenous fertilizer that
provides the nutrients to the growing plants in the system.
Aquaponics
system consumes only 10% of water required for regular farming. It
provides an ideal method for food production in the backyards of
houses.
