soil and water quality standards

1. SOIL AND WATER QUALITY STANDARDS

2. STANDARDS???????
 Technical standard, an established norm or requirement about technical
systems.
International standard, standards suitable for worldwide use.
 Successful aquaculture depends on providing animals with a satisfactory
environment in which they grow.
 Good initial conditions for aquaculture can be assured by selecting a site with
suitable soils and a high-quality water supply. An adequate environment must
then be maintained over the culture period so that animals will survive and grow
rapidly.

3. Physical parameter of soil
 Soil plays an important role in determining the fertility of fish ponds. The basic
criterion for selection of a site for construction of ponds having an idea of physical
properties of soil.
1. Soil structure: Soil fraction should be about 90% and stone and gravel should not
exceed more than 10%.
2. Soil texture: clayey loamy or sandy clayey is suitable for their cohesive property.

4. Chemical parameters of soil
The major chemical factors of importance are:
(a)pH
(b) Nitrogen
(c) Phosphorus
(d) Organic carbon and C/N ratio
(e) Calcium and potassium
(f) Micronutrients

5. SOIL ACIDITY
Ideal pH range varies from 6-8.
Acidic pond do not respond well to fertilization.
Liming is the only way to improve water quality.

7. Nitrogen
 About 99% of the combined nitrogen in the soil is contained in the organic
matter (humus) in the form of amino acids, peptide and easily decomposed
proteins.
 It may also be in the form of inorganic compounds such as NH4
+ and NO3
-
which are utilized by phytoplankton. The range of available nitrogen 50 – 75
mg/100 gm of soil is relatively more favourable for pond productivity.

8. Phosphorus has
been called “the key
to life” because it is
directly involved in
most life processes.
Phosphorous
Phosphorous content productivity
<3mg/100gm(30ppm) Poor productive
3-6 mg/100 gm (30-60ppm) average productive
6-12 mg/100 gm (60-120
ppm)
High productive
>12 mg (120 ppm) Poor productive

9. Carbon and Nitrogen ratio
 Organic compounds present in the soil exert a profound influence on
almost every facet of the nature of soil.The significance of organic
fertilizers lies in their carbohydrate content.
 The nitrogen fixation stops when carbohydrates are absent in the
organic compound.
 The bacterial activity is low when C/N ratio falls below 10:1 and high
when the ratio is 20:1 or higher.

11. Calcium and Potassium
Calcium is generally present in the form of CaCO3 .It helps in
translocation of carbohydrates, acts as an integral component of plant
tissue, increase the availability of other ions and reduces the toxic effect
of single salt solution of other elements. CaCO3 deposition in fresh
water called as marl.
Potassium is taken up readily by submerged weeds for growth. During
rapid plant growth period, potassium from the water and soil is stored
in the tissues.
*Ca, K should present in a very negligible amount.

12. MICRONUTRIENTS PRESENT IN SOIL
1. Zinc - 0.75 -1.00 ppm
2. Cobalt 0.10-0.20 mg/li
3. Manganese less than 0.3 mg/li
4. Copper 0.001 to 0.01mg/li
5. Fe 0.01mg/li

13. PHYSICAL PARAMETER OF WATER
1. Depth of the pond- ideal pond depth should be 1-2m.
2. Turbidity: 25-30 cm.
3. Light penetration: 1000 Lux.
4. Temperature – 24-30ºc.
5. Current velocity should not be more than 10cm/sec.
6. Odour
7. Colour
8. Average plankton production- 10-20ml/m3.

14. Turbidity
 Turbidity range from 30-80 cm is good for fish health;.
 15-40 cm is good for intensive culture system
 < 12 cm causes stress.
 The secchi disk transparency between 30 and 40 cm indicates optimum
productivity of a pond for good fish ...

15. TEMPERATURE
 The solubility of oxygen and other gases will decrease as
temperature increases.
 For a tropical fish tank, maintaining a warm environmental temperature
ranging between 75 and 80 °F (24 to 30 °C) enables the fish to grow
properly.
 Coldwater fishes are salmonids and trout. Their optimal temperature
range is 10-16˚C .
 Air breathing fishes and common carp also tolerate 41ºc.

16. CHEMICAL PROPERTIES OF WATER
1. pH
2. Dissolved oxygen
3. Alkalinity
4. Hardness
5. Redox potential
6. Macronutrients
7. Micronutrients

17. pH=-log H+.
0-7 acidic 7 as neutral 7-14 alkaline.

18. Dissolved oxygen
DO refers to the level of free oxygen present in water.
It is an important parameter in assessing water quality because of its influence on
the physiology organisms living in water organisms who use oxygen in respiration.
 Microbes such as bacteria and fungi also require dissolved oxygen. These
organisms use DO to decompose organic material at the bottom of water body to
reduce toxicity.
Dissolved oxygen
Below 3.0 ppm Unproductive
3.0 – 5.0 ppm Average productive
6.0 – 5.0 ppm High productive.

19. ALKALINITY
 Total alkalinity is the sum of titratable bases in water. In most
waters, (HCO3) and carbonate (CO3
2-) are the predominant bases
that contribute to alkalinity.
 Total alkalinity is expressed as equivalent CaCO3 (mg/li).
 The alkalinity of pond waters is determined by the quality of the
water supply and nature of pond bottom soils.
 It should be in a range of 75-300mg/li for better production.

20. HARDNESS
Hardness is the measure of divalent cation(Ca Mg) present in water.
That should be in a level of 60mg/li for good productivity.

21. REDOX POTENTIAL
 Redox potential is an expression of the oxidising or reducing power
of solution.
 Dependant on nature , which invariably dependant on
temperature &pH.
 Redox potential generally lies between 0.4-0.5 volt.
 0.52 volt at 25ºc is the best value of redox potential for aerated
water at 1atm pressure.

22. ORGANIC MATTER
Organic matter found in pond water are
1. Inorganic phosphorous
2. Inorganic nitrogen
3. Carbohydrates
4. Vitamins
* These organic matter may be derieved from water may be allochthonously,
or autothonously.

23. CARBON IN WATER
 Carbon dioxide (C02) is a highly water-soluble, biologically active gas it should
be present in a lower amount in water as it cause reduction in water pH.
Dissolved CO2 is of interest in aquaculture because,
(1) It is a nutrient required for plant growth
(2) It can be a stressor of aquatic animals,
(3) It influences the pH of water,

24. Total ammonia nitrogen
TAN consists of two fractions:
1. Un-ionized ammonia (NH3) in free form
2. Ionized ammonia in the form of NH4
+
 Unionized ammonia is more toxic and it depends on water temperature and
pH.
 Higher the TAN higher is the unionized form and highly toxic. Nitrate
should be present as low as 0.01%.
 0.02-0.05%mg/li (0.03-1.3ppm) is safe for tropical fish species

30. Questions????