Raising freshwater crabs in cement tanks at home: Detailed guide and current situation.

Raising freshwater crabs in cement tanks is a model chosen by many households due to its high economic efficiency and ease of implementation. This article will provide you with detailed instructions on how to raise freshwater crabs in cement tanks, along with the current state of freshwater crab farming.

1. Prepare the cement tank and environmental conditions.

• Cement tank: The size of the tank depends on the area of ​​your house, but it needs to be at least 50cm wide and 1m high. The tank must be cleaned and disinfected before releasing the crabs.
• Environmental conditions:
  • Water: Use fresh, chlorine-free water with a pH of 6.5 to 8. Water should be changed every 2 days, and the water level should always be above 4cm.
  • Temperature: The ideal temperature for freshwater crabs to thrive is 25-27°C. The tank should be covered to protect it from direct sunlight and keep the crabs warm in winter.

2. Selecting and Releasing Crab Spawn

• Selecting crab spat: Choose healthy, uniformly sized crab spat measuring 1.2 – 1.4 cm (approximately 350 – 400 crabs/kg). Purchase spat from reputable farms to ensure quality.
• Storage Density: The average stocking density is 20 – 30 crabs/m². It’s best to release the crabs in the early morning or late afternoon.

3. Food and feeding methods

• Food: Freshwater crabs are omnivorous; their diet can include roasted bran, organic matter, rice flour, dried peanuts, snails, small fish, worms, etc.
• Feeding method:
  • First stage (first month): Feed cooked cornmeal twice a day (morning and evening), 5% of the ration.
    Stage 2-4 months: Supplement with golden apple snails, commercial feed, cornmeal, 7% of the ration.
  • Stage 4-6 months: Increase the ration to 10%.
  • Feeding times: 5 AM and 6 PM.

4. Tank Cleaning and Crab Care

• Tank Cleaning: Change water every 2 days, remove leftover food and debris. Thoroughly clean the tank after each breeding cycle.
• Care:
  • Monitor the crabs’ health regularly, remove weak or sick crabs.
  • Supplement the crabs with vitamins and minerals periodically.
  • Prevent and control diseases in crabs.

5. Harvesting Crabs

• Freshwater crabs can be harvested after 9-10 months, when they reach marketable size (50-55 crabs/kg).
• Harvest in the early morning or late afternoon, selecting firm, healthy crabs with plenty of meat.

6. Current status of freshwater crab farming

• Raising freshwater crabs in cement tanks is becoming increasingly popular due to its high economic efficiency and ease of implementation.
• However, there are also some challenges such as:
• • The price of freshwater crabs can fluctuate greatly depending on the season.
    Freshwater crab diseases can affect productivity.
  • Suitable farming techniques are needed to ensure healthy crab growth.

Raising freshwater crabs in cement tanks is a potentially profitable model for farmers. However, thorough preparation in terms of farming techniques and market demand is necessary.