Water is the most fundamental factor in fish rearing and the performance of fish and growth is determine by water quality. Yes! In fact it obvious to say that no water no fish! Some of the parameters or variables that make the water environment optimal and conducive for fish farming are: temperature, salinity, pH, ammonia. The rest are nitrate, nitrogen and Hardness in Water Quality Management leading to quality fish rearing.
Most Important Factors Water Quality Management In Fish Farming
- Temperature in Water Quality Management: This is a measure of degree of hotness or coldness of a body. It poses serious challenges to poikilothermic (cold blooded) animals. One area it mostly affects is Reproduction. Another area that is great important is their sexual maturing. Metabolism growth and food digestion in fish are affected by temperature as well. For every 10% increase in temperature rates of biochemical more or less double. Activities of fish increases with temperature as they eat, move, utilize more oxygen and grow faster. A critical level however is reached when diminishing returns set in such indicators are stress; slowness of growth retrogression, diseases, death may result.
- Salinity in Water Quality Management: This is the total concentration of all dissolved ions. Conductivity of water body increases with salinity. Fresh water generally 10-500mg/l. the unit measurement is part per thousand (ppt). Slow adaptation is possible if gradual change 1g/l/ day in fish up to critical levels for both fresh, brackish and marine species.
- Dissolved Oxygen (DO) in Water Quality Management. This is the master factor or the most critical factor that fish farmer contends with. Every living thing must have oxygen naturally. I am glad to let you know here that fishes therefore cannot be an exception. The lethal levels vary from just less than 1m/l to about 3mg/l while sub lethal level (example around 4mg/l) can cause stress, retard growth and predispose fishes to diseases. Photosynthesis by algae in water and diffusion at the methods through which oxygen enters the water. Compressors, blowers and paddle wheel aerators in association with mechanical generation, all can be used as means to get oxygen into the water and indicate whether the fish. Many fishes die at pH 4 or 10 and above. pH alone and especially in interaction with other variable is a critical water quality parameter in fish farming.
During photosynthesis at daylight, phytoplankton removes carbon dioxide while all the living organisms add carbon dioxide to the water as they respire.
- Alkalinity In Water Quality Management: This is defined as the quantity of bases present in water, essentially carbonate and bicarbonate. The measurement is in mg/l of CaCO3 Water with low alkalinity example20mg/l is poorly buffered and is generally unproductive in fish farming. The best range is 50-20mg/l CaCO3 and water with over 250mg/l CaCO3 are generally less productive.
- Hardness Of Water in Water Quality Management: This is the total concentration of metal ions (mainly Ca and Mg in water and also expressed as mg/l CaCO3) best range is between 20-250mg/l. Alkalinity and hardness values similar in aquatic environments while calcium, oxygen, magnesium, carbonate and mostly in the water.