Bottom clean Aquaculture method is considered an updated version of bio-floc. The most important tasks here are scientifically removing the waste from the bottom of the reservoir and the rotation of oxygen and food supply to the fishes In this type of culture system, as the amount of oxygen is higher, it is able to culture fishes 10- 20 times more.

1. Bottom clean Aquaculture
system and It’s Engineering
Principle
Presented by
Degonto Islam
Department of fisheries and marine science
Noakhali science and technology university

2. Contents
• Principles
• Types of bottom clean fish farming pond
• Construction design of Circular and Raceway pond
• Maintenance
• Production
• Harvesting
• Problem associated with Bottom clean aquaculture system

3. Introduction
• Bottom clean Aquaculture method is considered an updated version
of bio-floc.
• The most important tasks here are scientifically removing the waste
from the bottom of the reservoir and the rotation of oxygen and food
supply to the fishes
• In this type of culture system, as the amount of oxygen is higher, it is
able to culture fishes 10- 20 times more.

4. Principles
• Fish waste disposal is the prerequisite for bottom clean method. The
main principles of this method is the cleaning the excess wastage
materials that causes ammonia toxicity and other gas or toxic.
• It involves making a clear natural circulation of water that accumulate
the cumbrous wastage at the mouth of drain point and facilitates it
pumped out scientifically through outlet pipe before Increase of
ammonia that make ammonia toxicity which is very harmful for fish.

5. Site selection
• All animals in the world, including fish, depend on having a healthy habitat.
Like all other animals raised or bred for food, fish also need some basic
necessities to survive, and a better, more suitable environment is one of the
most crucial requirements for a healthy life that will ultimately increase
biomass and result in good production or yield. Before beginning culture,
choosing a site is crucial in aquaculture. The physio-chemical characteristics
of the suggested site for culture must be taken into account. When choosing
a location, another factor should be taken into account, such as
socioeconomic factors.

6. • However a place with the following characters under different headings may
consider suitable for bottom clean aquaculture-
Physico-chemical characteristics:
• • The chosen location's soil must have sufficient water-holding capacity,
meaning it can hold enough water to fill the body of water.
• • Loamy or clay-loamy soil is regarded as being beneficial and fruitful for
aquaculture.
• • Due to excessive turbidity, particularly during the rainy season, red soil areas
shouldn't be chosen

7. • .• The location of the cultural water body should allow for proper and
simple management.
• The dyke needs to be tall and sturdy enough to block floodwater from
entering the water body
• • The location must be exposed to direct sunlight for 7-8 hours per day.
• • The water body's bottom mud level must be less than 15 cm for
freshwater prawn culture.

8. • Socio-economical characteristics
• • There should be electricity facilities available in the culture location. •
The communication system should be effective enough to carry various
inputs, yields, and other necessities during culture.
• The presence of a fish market is required, and it must be close by. Through
affordable transportation and simple selling, it will be very advantageous.
• The chosen region must offer all fishing inputs.
• A key factor in choosing a location is the strong demand for the product(s)
of cultured fisheries in the targeted areas.

9. Other considerations:
• • If chosen location is chosen closer to locality, it would be better
because security can be provided more easily than if chosen location
is chosen farther from locality.
• • Selected site or place should be free from risk of flooding and
drought during rainy and summer seasons, respectively.

10. Types of bottom clean fish farming pond
Circular shape ponds Raceway ponds
Source: Shykh Seraj, Chennel I

11. Construction design of Circular pond

12. Construction of Raceway pond

13. Pond Design
• It's time to decide on the design of the tanks after the site has been chosen,
surveyed, and the producer has determined the number and sizes of tanks
required when the farm is fully operational. When designing tanks, choices
should be made regarding the following:
• • The length, width, and water depth of the tank's water surface;
• • The total depth of the pond at the deep end;
• • The slope of the dykes and the tank bottom;
• • The size of the free board (the height of the dyke above water level);
• • The width of the dykes

14. Construction
paved with concrete
Round shape
Round shape pond have great advantage
that the dike wall will tolerance the water
pressure as water turns very quickly making
a circular pattern.

15. Bottom clean procedure
• In the center of the pond, there is a structure that resembles a toilet. It is
extremely deep. The house is 7 feet deep, however. Here, all of the fish waste
is collected and stacked. An aerator creates a racetrack. Therefore, one can
use a mud pump to remove waste and dirty water every two to three hours.
The entire bottom of the house has been cleaned. In the sizable reservoir
tank, a pipe has been set up. One end of pipe one is in the waste pond, and
the other end is in the center of the pond. There is a mud block machine set
up. The device drains out all of the waste that is gathered at the bottom of
the pond after sucking it in.

16. • . The device drains out here after sucking in all the waste that has
accumulated at the pond's bottom. It eliminates the pond's dirty water,
which is full of fish waste and feces. In this instance, all novel techniques
aim to completely purge ammonia from the water. The bottom clean
method requires the removal of fish waste. And it's done here very
effectively. I run the machine a little longer to change the water and get
rid of the waste if the ammonia level is above 0.5 in order to control it.

17. Middle toilet like outlet hole

18. Raceway of water
Paddle wheel aerator

19. Oxygen Circulation :
• The foremost conditions of modern fish farming are to ensure a fish waste
drainage system and increase oxygen supply.The oxygen is coming after creation.
These transparent pipes( figure:) go into the water.The oxygen is supplied to the
water through these pipes.Over there, oxygen coming out as bubbles in the water
through thin pipes.Meaning, the oxygen is coming out from underground. Also,
aeration allows the water to circulate continuously inside this round pond or
tank.The circulation created oxygen. Also,fish always swims against the tide.So,the
more the fishes swim, the more they get tired,hence the more they eat which
increase their growth.

20. Water In and disposal
• When the ammonia level exceeds 0.5ppm the pump should be run and
new water is added to the pond.
• The mud-block pump sucks in the bottom and piled up all the wastage and
drained out. This is done in every 2-3 hours

21. A toilet -like house is created in the middle of the pond.
All the fish waste gets centralized and stacked up here
A pipe is settled in the large reservior
Pipe one's end is in the waste pond and other end of
this pipe is at the toilet like house of the pond
A mud block machine is placed there

22. The machine sucks in all the wastage piled up at the bottom
of the pond and drains out
It cleans out the dirty water which contains fish excrement
and faeces from the pond
As a Raceway is made by aerator so one can pump the dirty
water in every 2-3 hours.

23. Production
• According to Galanda Fisheries, Rajbari, Bangladesh, In bottom clean
aquaculture, it is estimated 1.2 : 1 = feed : fish.
• An estimation for 50 acres: 1 lac shing and gulsha, 10 thousand rui.
• Total production in Galanda fisheries Ltd. Was about 300 ton per year
in 2018 and production investment was replenished within one year.

24. Harvesting
• In bottom clean aquaculture system two times harvest can be
possible throughout the year. Due to low temperature fish culture
and harvest in winter are cumbersome. Although entrepreneurs
(Sheikh Nijam, Owner of Gualanda Fisheries) demonstrated that it is
possible to harvest even three times a year with this method.
• Polyculture is the best option in bottom clean culture system. Carp
with shing or gulsha

25. Problem associated with Bottom clean aquaculture
system
• Large amount of water needed
• Lack of knowledge and research
• Pumped water doesn’t used for second time
• Easily spread disease from pond to wild
• higher construction and maintenance cost
• need highly skilled manpower and intensive care

26. Conclusion
• In bottom clean aquaculture system the working principles are simple but
effective. Bottom Clean Aquaculture system can be a revolutionary change
in the aquaculture sector with proper maintenance. But in short of
knowledge it could create a cumbersome situation. There should have
conducted research before adapting the system.