The document provides information on preparing aquaculture ponds for production. It discusses the purposes of pond preparation such as reducing toxins and diseases. The main parts of the pond system include water reservoirs and grow-out ponds. The preparation process involves draining the pond, removing debris, disinfecting, drying, fertilizing to enrich plankton, and adding probiotics before filling and checking the water quality. Pond preparation aims to improve water quality and sustainability while maintaining biosecurity.

1. Ngo Xuan Tuyen MSc. National Breeding Center for Southern Marine Aquaculture (RIA2) E-mail: ngo.tuyen@gmail.com ASEAN Training Course on Aquaculture Production Preparation of ponds for aquaculture production March, 2010

4. 1. Purposes of Aqua-pond preparation ► Particularly significant for old ponds Pond preparation can reduce: Resident toxic gas Incidence diseases Improve and sustain the water quality Enhance benefic microbial Adding live food

5. 2. Main parts of pond culture system Water reservoir Grow-out pond Settling ponds Grow-out pond Grow-out pond Need to be prepare before crop running Need to be treated before discharging out

6. Ex: Characters of shrimp & Tra fish pond Seawater Freshwater Water 10 - 30 20 – 40 (70) Stocking density (/m 2 ) 3 - 15 100 - 300 Productivity (tons/ha) Water treatment Rearing period (months) Aeration Depth (m) Shape Area (ha) Main characters Reservoirs Rearing ponds 3 – 5 6 - 7 yes yes 1.5 - 2 1.5 – 4.5 Rec. or square Rec. or square 0.5 - 2 0.3 - 1 Shrimp pond Tra fish pond

9. (2) Bio-security: External & Internal barriers for aquaculture farm E1 . Farm frame I1 . Pond net frame Main gate E2. IN E3. OUT I2 . Farming wastes Settling ponds Grow out ponds Water reservoirs Houses I3 . Internal movements

10. Example 1. Maintain foot dips at the entrance of pond site (I). 2. The seeds may be transported in pathogen contaminated water (E) 3. Staff should be trained in hygienic prevention methods in fish farm (E+I) Entry gate with vesicle bath

11. 4. Procedure of Grow-out pond preparation Drained, Remove debris, renovating Disinfection, liming, apply minerals Drying (+ tilling) Killing predators & Disinfection Fertilizing: enrichment of plankton & bloom Add in Pre- /or Probiotics Filling Installing sub-constructs (aeration system,…) Check and improve water quality

12. Waste water of Tra fish ponds -> watering the rice fields -> good results (Phung et al. 2008) Step 1 Drained, remove debris, till, prepare pond dikes, lining, put net frame (a) Draining the ponds Waste water of shrimp pond -> discharged into settling ponds

13. (b) Remove sludge (debris) and washing the bottom Garden of mango tree Tra fish pond Sludge of Tra fish ponds -> can use to grow up the fruit trees, vegetables, rice->↓ use of synthesis fertilizers (Sickney, 2000)

14. Sludge of shrimp ponds -> discharged into sludge reservoirs (right); Flushing the pond

15. (c) Prepare pond dike, gates, lining, put the net frame Renovate, clean, smooth the pond dikes: - Water level: 1 - 2m - Prevent the pond from water leaking

17. (d) Prepare the pond bottom -> slope towards the drain (central canal) or to one end of the pond at the harvest gate. (Stickney, 2000) Cross-sectional diagram of pond (right) and different side slopes (left)

19. (2) If the pond cannot be completely dried: Disinfection by apply chemical & liming apply an approved chemical to the remaining waters Ex: Chlorine dioxide at 2 mg/l ->to ensure sterilization of ponds

20. < 60 kgs/ha Ca(OH) 2 Slaked lime Hydrated lime Builders lime < 60 kgs/ha CaO Quicklime Burnt lime > 10 tons/ha CaCO 3 , MgCO 3 Pelletized lime > 10 tons/ha CaCO 3 Crushed oyster shells > 10 tons/ha CaCO 3 , MgCO 3 Dolomitic lime > 10 tons/ha CaCO 3 Calcitic lime App. rates Active Ingredients Lime Type Types of limes and recommended rates of application for aquaculture ponds (Wing et al., 2004)

23. Step 4 Installing sub-constructs Aeration system: ↑ DO levels -> ↑ intensification ↑ Breakdown organic compounds Mixing the water body

25. Several forms of mechanical aeration: (3) Venturi aerator (5) Agitator Source: Aquatico, UK (4) Airlift pumps (Wing, 1999)

27. Filtering water through filter bags Cross section view Illustrations of Inlet gate (Fox, 2005) Above view

30. Some of chemical disinfectants (i.e. chlorine) are NOT recommended using in the growout ponds : poor pond bottom; accumulate organic toxic compounds

33. Types of inorganic fertilizers (Knud-Hansen, 1998)

35. * Day 1 is the first day the pond is being filled. **For ponds with calcium hardness below 50 mg/l, use the lowest rate. Ludwig et al., 1998 4 – 8 9 – 18 60 21 4 – 8 9 – 18 60 14 If needed… 4 – 8 9 – 18 60 8 7.5 – 15 * * 18 – 36 ** 280 1 10 – 30 – 0 0 – 49 – 0 11 – 37 – 0 12 – 49 – 0 (liquid or powder) rice bran, cottonseed meal, or alfalfa pellets ( required a disinfection ) (Organic fertilizer (kg/ha) +) Inorganic fertilizer (kg/ha) Day *

38. Amplifying Probiotics Bacillus Step 8 Add in Pre- /or Probiotics Many types are already commercial

39. Last step Check and improve water quality 2. Qualitative parameters: Color Exist of toxic algae EX: Total alkalinity If <20 mg/l ->liming If 20 - 50 mg/l ->benefit from liming If 50 mg/l ->do not require liming 1. Quantitative parameters: Depth Clarity pH Total alkalinity Dissolved oxygen Hung, 2009

40. Liming: ↑ alkalinity - pH buffering Buffering – sustaining the water pH If pH ↑: H + + HCO 3 -  H 2 CO 3 + H 2 O + CO 2 If pH ↓: OH - + H + + H 2 CO 3  HCO 3 - + H 2 O Agriculture lime [CaCO 3 ] or/and Dolomite [CaMg(CO 3 ) 2 ], 100 - 200kg/ha

41. pH vs. toxins in pond water Toxicity of NH3-N: cause gill irritation and respiratory problems ↑ pH one unit ► ↑ 10 x (amount of toxic by NH 3 ) P roper timing of fry stocking after fertilizing is very important: - food particle size ->appropriate sizes for fish fry - abundant natural food organisms

43. 5. Procedure of water reservoir preparation Drained, Remove aquatic plants, prepare pond bottom & dikes, net frame Liming & Drying Killing predators & Disinfection Fertilizing Add in Pre- /or Probiotics Filling water with filter bag Check and improve water quality If needed

44. Inlet gate design for reservoirs Bôø ao Water current Water level 5 1 2 3 4 Water sources Reservoir 1. Wooden layer-opening the bottom gate 2. Filter net (mesh < 2 mm) 3. Fish egg filter net 4. Wooden barrier – decrease the velocity 5. Filter net (mesh >10 mm

45. End. Thank you for your listening!