Sankalchand Patel Collage of Engineering, Visnagar GUJARAT TECHNOLOGICAL UNIVERSITY Chandkheda, Ahmadabad Sankalchand Patel Collage of Engineering, Visnagar Department of CIVIL Engineering

Group Member Name Enrollment no Patel Khushbu B. 130400106067 Patel Krupaben V. 130400106068 Prajapati Rutu S. 130400106091

WATER QUALITY What You Need To Know To Keep Your Fish Alive Gary Fornshell, University of Idaho Terry Patterson, College of Southern Idaho

To a great extent, the success or failure of fish culture is determined by water quality

Water Quality – Why Is It Important? Your fish live in it Are supported by it Receive their oxygen from it And excrete in it 3 5

Water Quality – Why Is It Important? Water quality factors influence and interact with each other What may cause problems in one situation may be harmless in another Influences effectiveness/toxicity of treatments

Water Quality – Why Is It Important? Most disease problems can be avoided with proper management of water quality This includes maintaining water quality at a level that provides an environment conducive to fish health and growth

Water Quality Variables Temperature Dissolved oxygen Total ammonia-nitrogen, NH3, NO-2 Alkalinity Hardness pH Carbon dioxide

Water Quality Variables Temperature For each 10°C (18°F) rise in temperature the metabolic rate doubles Controls the reaction rate of chemicals Influences solubility of gases in water Influences toxicity of ammonia and therapeutants Optimum temperature for tilapia growth is 85-88 °F

Water Quality Variables Dissolved Oxygen First limiting factor for growth and fish health Solubility decreases with increasing temperature and elevation Respiratory rate increases with increasing temperature, activity and feeding In general the minimum DO should be ≥ 60% of saturation or ≥ 5 ppm (mg/L) > 2 ppm in biofilter effluent

Water Quality Variables Total Ammonia-Nitrogen Usually the second limiting factor – nitrogenous waste: feces & feed TAN includes ammonium ion (NH4+) and ammonia (NH3) The proportion of NH3 increases with increasing temperature and pH < 0.05 mg/L NH3 < 0.5 mg/L nitrite-N (NO-2) ,

Percent of Total Ammonia in the Un-Ionized Form at Various Temperatures and pH percent Ammonia Temperature (ºF) (pH) 7.0 8.0 9.0 ___________________________________________ 50º 0.19 1.83 15.7 68º 0.40 3.82 28.4 86º 0.80 7.46 44.6

The Nitrogen Cycle Food Water plants Excess food Fishes Algae Feces Peptides Amino acids Urine Urea Ammonia (NH ) Algae Nitrate (NO ) Nitrite (NO ) Feces 2 3

for Bio-Filter to Mature Time Required for Bio-Filter to Mature 0.8 8 NO 3 0.6 NO 6 2 NH 3 Nitrites & Nitrates (mg/l) Ammonia (mg/l) 0.4 4 0.2 2 0.0 2 6 10 14 18 22 Time in Days 22 14

Water Quality Variables - Alkalinity Is the buffering capacity of water – absorbs acids and/or bases High alkalinity prevents wide pH fluctuations Maintain levels between 75-120 mg/L as CaCO3 7 grams of alkalinity consumed by 1 gram of NH3

Effects of pH on Various Buffers Percent of Total CO 2 100 - = Free CO HCO CO 2 3 3 50 4 5 6 7 8 9 10 11 12 pH

Water Quality Variables Hardness 50 – 100 mg/L as CaCO3 pH 7 – 8 Carbon dioxide < 20 mg/L