“If you define the problem correctly, you almost have the solution.”
– Steve jobs
ZENITH AQUATECH, established in 2015, based on Kolkata,
West Bengal. ZENITH AQUATECH started more than a decade
ago with two graduates, but now consists of a large team of
professionals.
ZENITH AQUATECH started as an aquaculture consulting
company. Through the years the activities have shifted towards
the design, supply and installation & commissioning of fish
farms and fish farming equipment.
Our mission is to design and construct efficient and reliable Recirculation Aquaculture Systems (RAS), Biofloc and Hydroponics culture to facilitate farming of tasty and healthy aquatic products with minimum impact on the environment. We are continuously doing R&D of new formulations and future development of cutting edge technologies, and finding new and sustainable ways that enhance the recycling process of nutrients and waste for applications in agriculture, aquaculture, waste water treatment and environmental remediation, to address global food production and environmental challenges.
In today’s world, ZENITH AQUATECH unprecedented challenges of
significant increases in the human population, unsustainable production
practices and inadequate environmental conservation.
Our aim is to become a global leader in aquaculture by:
Aquaculture consists of mainly Four segments......
RAS
AQUAPONICS
Aquaculture – Growing aquatic plants and
animals (fish, oyster etc).
Ponos – The Greek word for growing plants
with or without media.
Most people relate growing plants to hydroponics
since both use nutrient rich water and both use soil-
less media.
There are three main cycles taking place.
Fish are cultured as in any aquaculture system (and at the similar densities)
Recirculating aquaculture systems (RAS) are used for
fish production where water exchange is limited and the
use of mechanical and biofiltration is required to reduce
ammonia toxicity. Other types of filtration and
environmental control are often also necessary to
maintain clean water and provide a suitable habitat for
fish. The main benefit of RAS is the ability to reduce the
need for fresh, clean water while still maintaining a
healthy environment for fish. To be operated
economically commercial RAS must have high fish
stocking densities.
Mechanical & Biofiltration
All RAS relies on mechanical & biofiltration to convert ammonia (NH4+ and NH3)
excreted by the fish into nitrate. Ammonia is a waste product of fish metabolism and
high concentrations (>.02 mg/L) are toxic to most finfish. Nitrifying bacteria are
chemoautotrophs that convert ammonia into nitrite then nitrate. A biofilter provides a
substrate for the bacterial community, which results in thick biofilm growing within the
filter. Water is pumped through the filter, and ammonia is utilized by the bacteria for
energy. Nitrate is less toxic than ammonia (>100 mg/L), and can be removed by a
denitrifying biofilter or by water replacement. Stable environmental conditions and
regular maintenance are required to ensure the biofilter is operating efficiently.
Solids removal
In addition to treating the liquid waste excreted by fish the solid waste must also be
treated, this is done by concentrating and flushing the solids out of the system.
Removing solids reduces bacteria growth, oxygen demand, and the proliferation of
disease. The simplest method for removing solids is the creation of settling basin where
the relative velocity of the water is slow and particles can settle at the bottom of the tank
where they are either flushed out or vacuumed out manually using a siphon. However,
this method is not viable for RAS operations where a small footprint is desired. Typical
RAS solids removal involves a sand filter or particle filter where solids become lodged
and can be periodically back flushed out of the filter. Another common method is the
use of a mechanical drum filter where water is run over a rotating drum screen that is
periodically cleaned by pressurized spray nozzles, and the resulting slurry is treated or
sent down the drain. In order to remove extremely fine particles or colloidal solids a
protein fractionator may be used with or without the addition of ozone (O3).
Aeration
Aerating the system water is a crucial part to obtaining high production densities. Fish
require oxygen to metabolize food and grow, as do bacteria communities in the biofilter.
Dissolved oxygen levels can be increased through two methods, aeration and
oxygenation. In aeration air is pumped through an air stone or similar device that
creates small bubbles in the water column, this results in a high surface area where
oxygen can dissolve into the water. In general due to slow gas dissolution rates and the
high air pressure needed to create small bubbles this method is considered inefficient
and the water is instead oxygenated by pumping in pure oxygen. Various methods are
used to ensure that during oxygenation all of the oxygen dissolves into the water
column. Careful calculation and consideration must be given to the oxygen demand of a
given system, and that demand must be met with either oxygenation or aeration
equipment.
pH Control
In all RAS pH must be carefully monitored and controlled. The first step of nitrification in
the biofilter consumes alkalinity and lowers the pH of the system. Keeping the pH in a
suitable range (6.5-8.5 for freshwater systems) is crucial to maintain the health of both
the fish and biofilter. pH is typically controlled by the addition of alkalinity in the form of
lime (CaCO3) or sodium hydroxide (NaOH). A low pH will lead to high levels of
dissolved carbon dioxide (CO2), which can prove toxic to fish. pH can also be controlled
by degassing CO2 in a packed column or with an aerator, this is necessary in intensive
systems especially where oxygenation instead of aeration is used in tanks to maintain
O2 levels.
Temperature control
All fish species have a preferred temperature above and below which that fish will
experience negative health effects and eventually death. Warm water species such as
Tilapia and Barramundi prefer 24°C water or warmer, where as cold water species
prefer water temperature below 16°C. Temperature also plays an important role in
dissolved oxygen (DO) concentrations, with higher water temperatures having lower
values for DO saturation. Temperature is controlled through the use of submerged
heaters, heat pumps, chillers, and heat exchangers. All four may be used to keep a
system operating at the optimal temperature for maximizing fish production.
RAS – Advantages:
◉ Control of growing conditions: including temperature, water chemistry and
turbidity, disease, etc.
◉ Growth cycles: including shortened time to harvest, size of the species, quality of
product, as well as optimum harvest points and ability to plan for harvest.
◉ Control of outputs and effluents: treatment and the possibility of reuse as fertilizer
or input for other fish systems (in integrated aquaculture).
◉ Greater fish intensity: better feed consumption and control of metabolic rates, less
nutrient development from lost feed.
◉ Good control of water chemistry and temperature:
Low water use
High densities and productivity
It is an innovative and cost-effective technology in
which toxic materials to the fish and shellfish such as
Nitrate, Nitrite, Ammonia can be converted to useful
product, ie., proteinaceous feed. It is the technology
used in aquaculture system with limited or zero water
exchange under high stocking density, strong aeration
and biota formed by Biofloc. The culture of Biofloc will
be productive in the case of culture tanks exposed to
controlled sun light.
Biofloc system was developed to improve the
environmental control over the aquatic animal production.
TYPES OF FISH CULTIVATION
Following types of fishes has been grown using Biofloc technology in India. The cultivation
methodology is same as in Biofloc system but the process varies with respect to types of
fish as per its growth and environment required.
• Rohu / Catla
• Talapia
• Singhi
• Koi
• Bata
• There are many more
and people have also
started cultivating
ornamental fish.
SCOPE FOR FARMER AND SMALL ENTREPRENEUR
• Water used for first time harvesting could be used for the second harvest. Thus
water conservation becomes a vital advantage
• Farmers could cultivate multiple species in one tank or in separate tank in order to
diversify himself to adjust to the change in demand in market
• Land requirement is much more lesser than traditional pond cultivation. Farmers
could allot small portion of their farm land from their existing crop cultivation land to
setup a small scale fish farming plant
• Farmers could also setup the farm in any unused or uncultivated lands or any
closed factory shed.
• If government subsidy or government loan is made available for the initial setup.
OUR SUPPORT TO PROMOTE BIOFLOC
Biofloc has been an unorganised sector where there has been self claimed gurus to give
training to fish farmer or to those individuals who are looking to venture into fish farming.
Biofloc is successful and also unsuccessful in many ways. Success comes through use of
right methodology and components for each fish bread required. People have also faced
failures due to lack of proper knowledge. Mostly for first timers who work on DIY (Do-It-
Yourself) through youtube. We offer the following support which could work as key role:
• Supplying of components required to farmers as one stop solution.
• We can formulate pro-biotic which could be used by farmers without much hustle.
• We do provide training medium to impart off field or on field training at different locations.
• We do setup knowledge centre through the experience to trouble shoot problems
encountered by farmers during cultivation (e.g. cultivation of different fish breed, trouble
shoot if there is any disease outbreak).
• We can also supply seeds as well as an agency to procure all the harvest of the farmers
to streamline the farm to market transfer.
ECONOMICS FOR BIOFLOC SYSTEM (Approximate)
Projected fixed expense for 5 years
• Tank and its accessories = Rs.40,000/- to Rs.50,000/-
Recurring expense during harvesting
• Consumables (Probiotic, molasses, Testing materials etc) = Rs.8,000/month
• Fish Feed = Rs.37,200/ cycle
• Fish Seed = Rs.9,000/ cycle
There is no thumb rule of how much one could earn from biofloc fish tank in one harvest. The
following is the back calculation done through different survey of harvesting done by
individuals and organizations through out the country.
• In a tank a maximum of 1 ton fish can be harvested.
• This harvesting can be for 3 months or 7 months depending on the type of fish the total weight of fish
required.
• For Price of the fish depends on region to region could vary from Rs.100-200/Kg.
• Thus at an harvest we could collect Rs.1,00,000 – Rs.2,00,000/- per tank.
Note: This is an approximate cost analysis of a Biofloc tank. There may be other expenditure but still there is
a substantial amount of profit in this fish farming
A cultured pearl is a pearl created by a mussel farmer or
oyster farmer under controlled conditions. Cultured pearls can
be farmed using two very different groups of bivalve mollusk:
the freshwater river mussels, and the saltwater pearl oysters.
HISTORY:
For cultured Pearl Mikimoto Kōkichi was first to use Nishikawa's
technology. After the patent was granted in 1916, the technology was
immediately commercially applied to akoya pearl oysters in Japan in
1916. Mise's brother was the first to produce a commercial crop of pearls
in the akoya oyster. Mitsubishi's Baron Iwasaki immediately applied the
technology to the South Sea pearl oyster in 1917 in the Philippines, and
later in Buton and Palau. Mitsubishi was the first to produce a cultured
South Sea pearl – although it was not until 1928 that the first small
commercial crop of pearls was successfully produced.
DEVELOPMENT OF A PEARL:
A pearl is formed when the mantle tissue is injured by a
parasite, an attack of a fish or another event that damages the
external fragile rim of the shell of a mollusc shell bivalve or
gastropod. In response, the mantle tissue of the mollusc
secretes nacre into the pearl sac, a cyst that forms during the
healing process. Chemically speaking, this is calcium
carbonate and a fibrous protein called conchiolin. As the
nacre builds up in layers of minute aragonite tablets, it fills the
growing pearl sac and eventually forms a pearl.
Natural pearls are formed by nature, more or less by chance.
On the other hand, cultured pearls are human creations
formed by inserting a tissue graft from a donor mollusc, upon
which a pearl sac forms, and the inner side precipitates
calcium carbonate, in the form of nacre or "mother-of-pearl".
The most popular and effective method for creating cultured pearls are made from the
shells of freshwater river mussels harvested in the midwestern states of the U.S., from
Canada to the Gulf of Mexico. Shells with the common names, "Washboard" "Maple Leaf"
"Ebony" "Pimpleback" and "Three Ridge" are popular for use in pearl culture due to their
compatibility with the host animal, and the nacre they are to be covered by. These high-
quality and sought-after shells are first sliced into strips and then into cubes. The edges
and corners are ground down until they are a roughly spherical and then milled to become
perfectly round, and brought to a highly polished finish.
After the nucleus is ready, the next step is obtaining the mantle tissue. The mantle tissue
is harvested from one oyster and cut into small pieces. After obtaining the mantle tissue
from the first oyster it is time to operate on the second animal. The oyster is placed in
warm water to relax the animal. Then it is gently pried open and mounted in a stand to be
operated on. A small incision is made and the nucleus is inserted along with a small piece
of mantle gland. The oyster is then placed back in the water and allowed over several
years to coat the nucleus with nacre. The nucleus is coated in many layers of this nacre,
so that when pearls are cut in half, visible layers can be seen.
PROCESS TO PRODUCE CULTURED PEARL:
The process of pearl culture includes the following steps which are very crucial for
obtaining high grade of pearls with good commercial value.
Step 1: Construction of pearl farm
Construction of a pearl farm includes three steps. They are,
Selection of farm site: This step determines the type of pearls produced and the oyster
survival rate. Some of the points to be noted while selecting the site are:
o Natural features like mountains and reefs are needed to protect the farm from winds,
currents, storms etc.
o Constant regularity of temperature
o Type of sea bed, such as rocky or sandy.
o Gentle currents are essential for the survival of the oysters as they bring food and
oxygen.
Construction of pearl farm: The whole pearl farm system is based on series of floating
wooden rafts. Ten units of wooden rafts are used. Each raft consists of two to five pieces
of wood making the total length to 20 ft. The raft is covered with wire mesh baskets, each
of which house 10 oysters.
Well-planned work schedule: A typical work schedule plays a very critical role in pearl
culture. The timing for collecting and seeding the oysters must be scheduled and followed
strictly.
Step 2: Seeding
Two-three year old healthy oysters are considered for surgical implantation known as
seeding which are collected from market. This is a very delicate operation and involves
three stages:
Preparation of the graft: A donor oyster is sacrificed to obtain mantle. Mantle is needed
by the host oyster to accept the nucleus. The mantle is located on the outer section of the
oyster and Mantle produces the nacre which forms pearl.
Attaching the graft: The oyster is opened with special wedges and pliers, then a scalpel
slit is made in the soft tissue near the reproductive organ and a graft of living mantle is
inserted into the slit.
Inserting the core: A nucleus is placed in the scalpel slit and the oyster is then returned
back to the water. The inserted core irritates the oyster, provoking it to gradually coat the
core with thin layers of mother of pearl nacre.
Step 3: Caring the Oyester
The shells which have been collected and transferred to the pearl farm are placed in
baskets or panels which are attached to long lines connected to the floating rafts. The rafts
are dropped down into the ocean with the oyster securely inside the basket, where they
remain until they become operated on for further seeding.
The oyster can produce more than one pearl in its lifetime. Regular cleaning of the shells
to remove seaweed results in better pearls plus makes them easier to handle. The
cleaning is done by a machine which uses water jets and brushes to clean off any
seaweed. The oysters need very tender loving care so as to be productive when
harvested.
