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

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

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

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

5. 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

6. 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

7. 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

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

9. 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 °F

10. 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

11. 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) ,

12. Percent of Total Ammonia in the Un-Ionized Form at Various Temperatures and pH
percent Ammonia
Temperature (ºF) (pH)
___________________________________________
50º
68º
86º

13. 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

14. 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

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

16. 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

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