Water Quality Monitoring and Instrumentation - Antique Modules PDF

Water Quality Prepared by: Victor Marco Emmanuel Ferriols Institute of Aquaculture College of Fisheries and Ocean Sciences University of the Philippines Visayas What is water quality? General term for all the physical, chemical and biological...

Water Quality Prepared by: Victor Marco Emmanuel Ferriols Institute of Aquaculture College of Fisheries and Ocean Sciences University of the Philippines Visayas What is water quality? General term for all the physical, chemical and biological factors which influence the use of the water. In aquaculture water quality is important in terms of: Site selection Species to be cultured Optimum rearing conditions Major Water Parameters pH and alkalinity Salinity Dissolved oxygen Temperature Nutrients Nitrogen Phosphorous pH A logarithmic scale for expressing the acidity of a solution Measure of the amount of hydrogen ions (H+) in water Affects the capacity of blood to carry oxygen In relation to photosynthesis in ponds, pH also fluctuates on a daily basis depending on the amount of carbon dioxide in the system since higher CO2 levels make water more acidic pH Measured using pH meters or pH paper  Salinity The measurement of the total amount of salts in the water Expressed in terms of the weight of salts per volume of water (usually parts per thousand – ppt) Variations in salinity can cause stress and acute or chronic mortalities amongst fish stocks Organisms that can tolerate a wide range of salinities are called euryhaline while those that can tolerate only a narrow range are called stenohaline  Salinity Measured using conductivity probes, hydrometers, or refractometers  Dissolved Oxygen Oxygen gas which is in solution Important factor in the respiration of aquatic organisms Low levels of DO (below 2 ppm) could cause stress and death in fish due to asphyxiation Too much DO could also cause gas embolisms (gas bubble diseases) Dissolved Oxygen  Dissolved Oxygen Measured in terms of parts per million (ppm) using DO meters or the Winkler titration method  Temperature Measure using ordinary thermometers or temperature probes  TSS and TDS Total suspended solids Dry weight of suspended particles not dissolved in the water column Measured using filtration and gravimetric methods  TSS and TDS Total dissolved solids Any minerals, salts, metals, cations or anions dissolved in water Measured using a TDS meter (electrical conductivity)  Nutrients Play a major role in the overall productivity of an aquatic system Example of major nutrients are nitrogen (NO2, NO3, NH4) and phosphorous (PO4) Sources of nitrogen in water can be the atmosphere and the decomposition of fish waste and excess feeds Main source of phosphorous in fishponds would be the pond soil. Ammonia – Phenol-hypochlorite method Nitrate-nitrite – cadmium column reduction Phosphorous – Ascorbic Acid Method  Nutrients Generally measured using colorimetric / spectrophotometric methods Thank You!