The role of water in fish farming.

Water is the natural habitat of fish thus for successful farming venture,the quality must be monitored and controlled.The growth of any fish depends on the water parameters,feeding protocol,feed composition and genetic potential of the fish specie. The sources of water for the fish farming could be any of the following; wells,dams,boreholes ,sea/lagoon and streams.The system of farming intended will dictate the source of water to be used.The earthen pond usually get water from streams,sea/lagoon and channeled springs while the concrete ponds are filled either from wells,boreholes or dams.The most important factor to consider is the quality of the water source. Water for fish farming must possess the following qualities; 1) The PH must be between 7-9,not acidic or too alkaline. 2)The water must be clean and free from contaminants/pollutants such as oil,chemicals,paints or heavy metals. 3)It must be odorless,free from scumb or foam. 4)It must contain enough dissolved oxygen 4mg/litre. 5)It must have a temperature of between 25-32 degree . 6) The carbon dioxide must not be less than 5mg/litre. 7)Ammonia level 0.05mg/litre. 8)Nitrate not less than 50mg/litre. 9)Nitrite not less than 0.30mg/litre. Water quality should be checked at regular intervals using a water kit and necessary adjustment made,a change in any of the water parameters leads to stress in the fish which could lead to severe loses. Oxygen a major index of water quality needs regular monitoring and balancing.The reduced and increased levels of oxygen has a bad effect on the fish.When oxygen level is depleted in the pond,it leads to suffocation and death of the fish,while supersaturation leads togas bubble disease in fish.The supersaturation usually occurs in algae bloom,where there is rapid photosynthesis resulting in small bubbles accumulating in fish intestines,muscles and gills causing the fish to float. The management practices also hamper on the health of the fish,so these must also be taken into consideration in fish farming.