Category Archives: Tilapia

Pond Pumps and Filters

Pond Pumps and Filters

How to Select Pond Pumps

Pumps are very important in shrimp farming or for that in any fish farming operation. It would possibly not be wrong to say it is the most integral and vital piece of equipment in all recirculating aquaculture systems.

Pumps are essentially of two types : submersible and external pumps. The selection of the most appropriate pump depends on the size and scale of your shrimp farming operations. Generally submersible pond pumps can be installed very easily. However as regards efficiency external pumps score better than submersible pumps.

The most important factors when it comes to choosing pumps are their power consumption measured in watts and pumping capacity measured in gallons per hour. The initial cost depends greatly on these two factors. However it is important to keep in mind that greater efficiency is likely to result in power saving over a period of time. In order to achieve truly energy efficient operations it is good idea to go in for solar powered pumps either at the very outset and as early as possible in shrimp farming operations.

How to Select Pond Filters

Pond filters also comprise an important component especially in indoor shrimp farming operations. The functions of a filter are two fold: one is the removal of solid waste by process of mechanical filtration, and secondly biological filtration. A filtration system must be able to handle both requirements. Some filtration systems combine both mechanical and biological filters into a single system while in others the filtration occurs as a part of a two step process.

When choosing a filter it is important to remember that it is only one part of the system. The scale and size of the operations help to choose a filter.



Pond Aerator Systems

Pond Aerator Systems

Selecting Pond Aeration systems

Pond aerators are used to increase the level of dissolved oxygen in water. Water aerators are used to combat low oxygen conditions in lakes and ponds or in aquaculture tanks. Dissolved oxygen is a major indicator of water quality and a vital parameter in maintaining optimum productivity in shrimp and other fish farms. Grossly reduced oxygen levels may result in mass morbidity of aquatic life.

There are two common techniques to aerate a water body : surface aeration technique and subsurface aeration technique.

Natural Aeration

Natural Aeration results in surface as well as subsurface aeration techniques.

Surface aeration results from disturbance of the surface of water because of falling water such as from a falls, fountain or stream.

Sub surface aeration primarily occur via aquatic plants. Aquatic plants release oxygen into the water via the process of photosynthesis and thus support aquatic life.

Surface Aeration

Surface aeration is achieved via fountains, floating surface aerators and paddle wheel aerators.

Fountains help to enhance the aesthetic appeal of water bodies. However they are not so effective in increasing dissolved oxygen of a large water body in an appreciable manner.

Floating surface aerators work in a manner similar to fountains. Their ability to enhance oxygen levels are also limited. Further they do not enhance the appeal of water bodies as fountains do.

Paddle wheel aerators are most effective in increasing dissolved oxygen levels and as such they find maximum use in shrimp and other aquaculture operations.
They are powered by electric motors and mounted on floats. They are mostly used in outdoor shrimp farming.

Subsurface aeration

Subsurface aeration is achieved by means of diffused aerator systems. Diffused aerators utilise bubbles to oxygenate water. Bubbles are released at the bottom of the water body. As the bubbles rise to the top, aeration of the water body takes place.

Diffused aerators are classified into two types depending on the natures of bubbles they produce : course bubble generators and fine bubble generators.

Course bubble generators are generally much more inefficient in enhancing oxygen levels because of larger size of bubbles generated.

Fine bubble generators are extremely effective in enhancing oxygen levels. However one difficulty with fine bubble generators is that the diffusers may clog and therefore they need to be cleaned periodically to ensure their effectiveness. The problem is more in case the turbidity of the water is high. Fine bubble generators are frequently used in indoor shrimp farming.

Diffused aerators of various capacity depending on requirement may easily be obtained from Amazon.



Tilapia and Shrimp Polyculture

Tilapia and Shrimp Polyculture

Shrimp and tilapia aquaculture individually have proven to be very profitable in the last couple of decades, the prime reason being increasing demand all the time. So from the demand perspective, these businesses are immune to downside risks. However, being a biological produce there is always a risk, howsoever minimal of climatic, bacterial or viral factors affecting production.

Current shrimp farming practices are based on use of large and shallow ponds, with very low water circulation per day and no aeration, to raise a single shrimp crop. Shrimps dwell and crawl on the bottom of the ponds. As a result, the water volume remains largely unoccupied.

It is here that tilapia can be introduced and integrated into shrimp aquaculture. Tilapia can be introduced into the shrimp aquaculture system in two ways:

Shrimp and Tilapia simultaneous polyculture

Tilapia can be raised simultaneously with shrimp in the same pond. Each variety occupies a different teritorial niche within the same pond. Tilapia grows in the upper part of water while shrimps dwell at the bottom of the pond. The relationship between shrimp and tilapia is not competitive on feed and territory, but symbiotic. Tilapia feed on phytoplankton and zooplankton while shrimps on the bottom substrate. It is seen that introducing tilapia in shrimp ponds enhances shrimp growth.

Tilapia assists shrimp production by improving and stabilizing the water quality, cleaning the pond bottom and by having a probiotic type effect in the pond environment. Tilapia can reduce excessive phytoplankton biomass in later stages of pond culture and recycle nutrients effectively.

Shrimp and Tilapia polyculture by crop rotation

Shrimp and tilapia crop rotation can be practiced with an objective to minimise the possibility of viral epidemic in case of shrimp monoculture, thereby greatly eliminating risk of loss in production. In case of tilapia, they are largely resistant to viral epidemics.
Thus risk to business may be reduced while increasingly the chances of consistently higher production.