POND CONSTRUCTION & PREPARATION

1. Selecting the Pond Location

  • Location: Far from residential areas; not affected by domestic, industrial, or agricultural wastewater; must have separate water intake and discharge systems.

  • Transportation: Convenient for transporting materials, post-larvae, and harvesting.

  • Water source: Must secure a clean, unpolluted, and stable water source with suitable salinity (5–20‰).

  • Electrical system: Must have a strong and stable power supply, preferably a dedicated 3-phase electrical system.

  • Area: Must be large enough to build the full system: nursery pond, grow-out pond, settling ponds, and wastewater ponds.

 

2. Pond System Design

a. Design of the Nursery Pond (Ao Vèo)

Pond Size

  • Circular pond, 100–300 m² (radius 5.5–10 m).

Depth

  • 1.0–1.2 m, with a slope from pond wall toward the center.

Bottom Lining

  • Lined with HDPE tarpaulin ≥ 0.5 mm, covering the entire bottom and pond walls.

  • Install siphon and waste-collection systems at the pond center.

Pond Walls

  • Can be built with soil, steel frame, or concrete. Must be reinforced to prevent leakage.

Siphon Pit

  • Positioned at the center of the pond, 1–2 m in diameter depending on pond size.

  • Must be securely installed and capable of siphoning all accumulated waste.

  • Automatic siphon systems may be installed to better manage waste and toxic gases.

Roof/Cover System

  • Nursery ponds require a cover made of mesh or metal roofing sheets.

Aeration System

  • Paddlewheel aerators: 1–2 units, 0.5–1 tube length, 4–8 paddles depending on pond radius. Ensure paddle rotation reaches the siphon pit.

  • Bottom aeration: 40–60 m of nano aeration tubing (NANO AIR TUBE).

Water Intake & Discharge

  • Water intake: Must come from a dedicated settling pond and pass through a separate filtration bag to prevent pathogens.

  • Water discharge: In addition to the siphon system, install a drainage outlet to drain water quickly when needed.

 

b. Design of the Grow-out Pond

Pond Size

  • Circular pond, 500–2,500 m² (optimal: 1,000–2,000 m²).

Pond Shape

  • Circular ponds: Suitable for ponds <1,000 m² built with steel frames or concrete.

  • Square/rectangular ponds: Suitable for areas >1,000 m², usually built with soil embankments. Corners must be rounded to prevent dead-water zones and ensure proper circulation.

Depth

  • 1.5–2.0 m, with a slope from pond wall to center.

Bottom Lining

  • Fully lined with HDPE tarpaulin ≥ 0.5 mm.

  • Install siphon and waste-collection systems at the center.

  • Install fishbone drainage pipe system (>4 lines) beneath the liner to prevent the liner from floating during heavy rain or when punctured.

Pond Walls

  • Can be soil, steel frame, or concrete for smaller ponds.

  • Must be reinforced to prevent leakage.

  • Corners must be rounded to avoid accumulation of sludge and toxic gases.

Siphon Pit

  • Installed at the center, >2 m in diameter, depending on pond size.

  • Must be firmly installed and capable of completely removing waste.

  • Automatic siphon systems can be used for better waste and gas control.

Roof/Cover System

  • Ponds <1,000 m² may use mesh roof covers.

Aeration System

  • Paddlewheel aerators: 2–4 units, 1–3 tube length, 12–24 paddles depending on pond size and number of aerators. Paddle rotation must reach the siphon pit.

  • Bottom aeration: 100–200 m of nano aeration tubing depending on pond size and depth.

Water Intake & Discharge

  • Water intake: Must come from a dedicated settling pond, separate from the nursery pond system, with dedicated filter bags.

    • Should include two separate settling ponds to rotate water preparation.

  • Water discharge: Besides the central siphon, an additional drainage system is needed to release water rapidly when required.

 

c. Design of Settling Ponds

Settling System for Nursery Ponds

  • Can share the main settling system used for grow-out ponds.

  • Grow-out ponds may serve as “ready-to-use” water storage after treatment.

Settling System for Grow-out Ponds

1. Primary Settling Pond (Raw Water Intake Pond)

  • For initial water intake → chemical treatment → transfer to water holding pond.

  • Only requires HDPE liner along pond walls (≥0.3 mm).

  • Used for applying chemicals such as KMnO₄, CuSO₄, etc.

  • Size depends on available land.

2. Water Holding Pond

  • For long-term water storage and treatment using disinfectants and water-conditioning chemicals.

  • Constructed like a grow-out pond.

  • Volume should be 5–10 times larger than the total volume of grow-out ponds.

  • May install 1 paddlewheel aerator for water treatment.

  • Embankments may be raised to increase volume when space is limited.

3. Ready-to-use Settling Pond

  • Receives treated water → final treatment → supply directly to grow-out ponds.

  • Constructed similar to grow-out ponds.

  • Volume should be 2–3 times the capacity of grow-out ponds.

  • May install 1 paddlewheel aerator.

  • Embankments can be raised if the pond is small.

Design of Wastewater Pond

  • Used to contain untreated siphoned wastewater or dirty pond water before chemical treatment and discharge into the environment.

  • Size depends on available land; embankments can be raised to increase capacity.

  • Pond walls may be lined with HDPE ≥0.3 mm to prevent contamination of surrounding soil.

  • Must be located far from culture ponds and connected to the discharge system to avoid pathogen intrusion.