Introduction Any characteristics of water that affect the survival, growth, reproduction, or management of fish in any way is a water quality variable. Water quality includes all physical, chemical and biological factors that influence the beneficial use of water.
Water Source Tube well Diesel Pump Canal water Rain water Quantity: Initial Filling: 6000 cubic meter/acre or cubic meter/hectare Supplementary requirement depends upon the seepage and water quality.
Water Quality Parameters Physical Chemical Biological Physical: Temperature Light Turbidity Chemical: Oxygen pH Salinity CO2 Ammonia
Temperature The temperature is a most important factor for the growth of all organisms including fish, phytoplankton as well as zooplankton. Range of temperature imposes limitation upon the choice of fish. Reproduction, growth and breathing rates of fishes are directly dependent on temp. Indirectly effect on Dissolved Oxygen & pond productivity, pH, solubility of gases, etc. Measured with the help of digital thermometer.
Temp range of water for different species spawning & growth Water temperature rangeSpecies 10 0 CSalmon around 10 0 CPike around 12 0 CPerch CTilapia CMajor Carps CChinese Carps
Light One of the most obvious and familiar property of water is its transparency. The light penetration depends upon the dirtiness of water and angle of the radiations. Natural waters are never pure and contain many substances, which further interfere with light penetration. Is a complex environmental factors and penetration in water can produce diverse ecological effects. Phytoplankton, zooplankton, organic & inorganic particles reflect or absorbs light rays.
Contd… Light controls several aspects of plant life like structure, shape, physiology, growth and distribution In animals effects reproduction, development, growth, locomotion, migration and physiological processes Its main role is in photosynthesis, providing oxygen and food for fishes. Light exerts a profound influence upon the whole series of biological phenomena in nature. The variations in the light penetration as interpreted from secchis disc visibility It ranges between 30-60cm.
Turbidity Water Turbidity is caused either by a high content of solids such as clay particles, or due to excessive production of phytoplankton. When it is due to plankton is a good sign. Due to suspension of silt and clay particles, may be harmful Hinder light penetration and decrease pond productivity Measured with the help of turbidity meter Use Alum, Lime or Gypsum to reduce Indian major carps can tolerate turbidity upto 2000ppm
Dissolved Oxygen DO requirement of fish vary from species to species 5mg/lit – 11mg/lit Cold water fish have higher demand than the warm water Concentration below 3ppm prove lethal for most fishes Low oxygen is due to: Excessive use of manure Long period of hot weather High population density High water temp
Heavy growth of plankton and macrophytes Decomposition of organic matter Decrease occurs mostly during monsoon, at night How to improve? 1. By stirring up the water, aeration through agitators or aerators 2. By taking out some of the old water 3. Adding freshwater 4. Reducing greatly artificial feeding and manuring
pH. Concentration of hydrogen ions Best range 7-9 To decrease add gypsum To increase add lime A pH. of 5-6 will reduce appetite, growth and tolerance to toxic substances Fish become more susceptible to parasites, and diseases in acidic waters Below 4.0 will kill fish, phytoplankton, and most plants Low value is due to presence of strong mineral acids Alkalinity of water is due to presence of calcium salts
Contd.. pH of water = 7.0Water is pure or neutral pH > than 7.0Water is alkaline pH < than 7.0Water is acidic pH range are likely to be suited for good fish production An ideal and good fish pond water, however should have a pH range of pH 11.0 is lethal to fish
Carbon dioxide Essential for photosynthetic activity of plants Up to 15-20ppm no adverse effects on fish life Above 20 ppm lethal for fish Make Carbonic acid with water which decrease pH.
Salinity Total ions of dissolve salts Limits the abundance of fish directly and indirectly Indian major Carps< 1000ppm Common Carp<9000ppm Grass Carp<12000 Silver Carp<8000ppm Tilapia<30000ppm
Total Alkalinity The titrable bases in water, as equivalent to CaCO3 are referred to as total alkalinity. The titrable bases in water, as equivalent to CaCO3 are referred to as total alkalinity. The total alkalinity of water is mainly caused by Ca++, Mg++, Na+, NH4+ and Fe++ combined either with carbonates, bi-carbonates or The total alkalinity of water is mainly caused by Ca++, Mg++, Na+, NH4+ and Fe++ combined either with carbonates, bi-carbonates or occasionally shows a wide range of fluctuations in total alkalinity values depending upon the location, season, plankton population and nature of deposits.
Contd.. Alkalinity of water is mainly due to the presence of calcium salts in the form of carbonates and bicarbonates. Alkalinity of water is mainly due to the presence of calcium salts in the form of carbonates and bicarbonates. High alkaline waters can be improved by fertilizing water with sulphate of ammonia. High alkaline waters can be improved by fertilizing water with sulphate of ammonia mg/lit Low Production mg/lit Low Production mg/lit Medium Production mg/lit Medium Production mg/lit High Production mg/lit High Production
Carbonates & Bicarbonates Natural water contains more bicarbonates than carbonates. The CO2 in natural water reacts with bases to form bicarbonates. In turn, if CO2 is removed from solution, bicarbonates will dissociate to form more CO2.
Total Hardness Many workers consider hardness and total alkalinity are the same because both are expressed as CaCO3, however, hardness is the total of soluble Ca++ and Mg++. >15mg/lit Enhance growth <5mg/lit Causes slow growth)
TDS & Conductivity All salts present in water, influence osmoregulation of fish and reduce solubility of gases Conductivity gives some idea about availability of phosphate, nitrates and nitrites or pond productivity Total Alkalinity: amount of total calcium carbonates, magnesium, sodium, potassium (mg/l) mg/lit, show pond water productivity
Ammonia (NH3) Ammonia is a toxic compound, which is produced by fish metabolism and decomposition of organic matter by bacteria. Toxic level is 0.6 to 2.0 mg/Litre. In such cases freshwater supply should be arranged
Summed up of Good Pond water Water Parameter Ranges pH D.O ppm CO ppm Phosphates ppm Nitrates ppm Total alkalinity 100 ppm Planktons ml/cu.m Light penetration cm