How to Change Shrimp Pond Water: A Complete Guide to Maintaining Optimal Water Quality

In shrimp farming, maintaining water quality is critical to achieving high yields and healthy shrimp. One essential practice to ensure this is changing shrimp pond water. This article dives deep into the why, when, and how of water changes, offering actionable insights and strategies for shrimp farmers.

Why Change Shrimp Pond Water?

Water quality plays a pivotal role in aquaculture success. Changing shrimp pond water helps address various challenges, including maintaining optimal conditions for shrimp growth and mitigating harmful substances. Key benefits include:

1. Regulating Water Temperature
   During extreme weather conditions, water changes stabilize pond temperatures, ensuring shrimp thrive in their ideal thermal range.
2. Controlling Salinity Levels
   High salinity, especially during the dry season, can hinder shrimp health. Replacing pond water dilutes salinity, maintaining levels that support shrimp growth.
3. Increasing Dissolved Oxygen (DO)
   Proper DO levels are vital for shrimp metabolism. Changing water prevents hypoxia by replenishing oxygen levels.
4. Regulating Nutrient Content
   Excess nutrients can lead to algal blooms and unstable pond conditions. Water changes help balance nutrient levels and enhance ecological stability.
5. Reducing Harmful Substances
   Substances like ammonia, nitrate, and nitrite accumulate in pond water, posing risks to shrimp health. Regular water replacement reduces these toxic elements.
6. Removing Metabolic By-Products
   Accumulated by-products from shrimp metabolism can degrade water quality. Water changes minimize these pollutants, ensuring a cleaner environment.
7. Replacing Evaporated Water
   Natural evaporation and leaks can decrease pond water levels. Regular replenishment maintains water volume and stability.

Changing shrimp pond water helps maintaining optimal conditions for shrimp growth

When to Change Shrimp Pond Water?

Knowing the right time to change water is essential for effective management. Look for these indicators:

1. pH Fluctuations
   A pH change exceeding 0.5 or beyond the acceptable range signals instability. This warrants immediate water replacement.
2. Color Changes
   Abnormal water clarity, whether overly clear (>80 cm) or turbid (<30 cm), suggests a need for action.
3. Excessive Sediments
   A buildup of sediment at the pond bottom can harm shrimp. Changing water reduces sediment accumulation.
4. Plankton Blooms
   Overgrown plankton populations destabilize the pond ecosystem. Water changes help control plankton density.
5. Shrimp Behavior Changes
   Decreased feeding appetite or increased mortality indicates stress, which may be due to poor water quality.
6. Organic Matter Overload
   Accumulated organic matter can create harmful conditions. Water replacement mitigates this issue.
7. Vibrio Bacteria Levels
   Elevated Vibrio levels can lead to diseases. Changing pond water reduces bacterial concentration.

Scientific Methods for Shrimp Pond Water Exchange

Changing shrimp pond water is a delicate process that requires precision and understanding. A well-planned approach minimizes stress on the shrimp and helps maintain a stable environment.

Step 1: Monitor Water Parameters Before changing water, test parameters such as pH, ammonia, and salinity. Use the results to determine how much water to replace.

Step 2: Prepare Replacement Water Ensure the replacement water matches the pond’s current salinity, temperature, and pH. Gradual adjustment prevents shocking the shrimp.

Step 3: Partial Water Changes Instead of a full water replacement, remove and replace 10-20% of the water. This method reduces the risk of drastic environmental shifts.

Step 4: Aeration During the Process Keep aerators running to maintain dissolved oxygen levels throughout the change.

Step 5: Post-Replacement Monitoring After changing the water, recheck all parameters to ensure stability. Address any imbalances promptly to avoid long-term issues.

By following these steps, shrimp farmers can optimize water conditions while minimizing stress on their stock, leading to healthier shrimp and higher yields.

A well-planned approach minimizes stress on the shrimp and helps maintain a stable environment

Targeted Water Quality Control

Every shrimp farmer encounters challenges. Identifying and addressing these issues promptly can make a significant difference in yield and quality:

1. Algae Control in Low Salinity
   When salinity drops below 8 ppt, blue-green algae can dominate, causing oxygen depletion and shrimp diseases.
   Solution: Use BKC 800 (0.5 ppm), probiotics, and zeolite to control algae and absorb toxins.
2. Turbidity Management
   Turbid water affects photosynthesis and shrimp health.
   Solution: Increase water changes and use probiotics to settle suspended particles.
3. Toxic Gas Reduction
   Ammonia (NH3), hydrogen sulfide (H2S), and methane (CH4) build up in ponds.
   Solution: Increase aeration, use probiotics, and siphon waste from the pond bottom regularly.
4. Rainwater Management
   Rain can dilute pond salinity and cause stratification.
   Solution: Drain surface water after heavy rain, use zeolite for quality control, and start aerators immediately.

Maintaining Ideal Alkalinity and Pond Color

The color of pond water serves as an immediate indicator of water quality, directly influencing shrimp health and growth:

Alkalinity Adjustments

• Ideal alkalinity ranges: 90-130 ppm for black tiger prawns, 100-150 ppm for whiteleg shrimp.
• To increase alkalinity by 10 mg/L in a 5000 m³ pond:
  Use 82.75 kg of dolomite lime (calculated with the formula: Volume × 1,655 × Desired Increase ÷ 1000).
• Alternatively, mix dolomite with soda lime (70:30) for more efficient results.

Achieving Brownish Green Pond Water
Brownish green water indicates balanced plankton populations beneficial for shrimp.

• Apply fertilizers like urea and dolomite as needed.
• Manage plankton density through regular water changes and aeration.

Key Considerations for Shrimp Pond Water Management

Effective shrimp pond water management requires an understanding of water quality indicators and proactive interventions to maintain a healthy aquatic environment. Below are key aspects to consider for shrimp pond water management:

1. Conduct Routine Water Parameter Monitoring
   Parameters like pH, salinity, DO, and nutrient levels should be checked frequently.
2. Optimize Feeding Practices
   Overfeeding increases waste and nutrient levels. Adjust feeding schedules, especially before and after rain.
3. Use Beneficial Microorganisms
   Probiotics and photosynthetic bacteria improve water and sediment quality, reducing pathogen risks.
4. Avoid Over-Draining Water
   Limit water exchange to 30% to prevent drastic changes that stress shrimp.

Conduct routine water parameter monitoring

Conclusion

Changing shrimp pond water is a critical component of aquaculture management, promoting a healthy environment for shrimp growth. By understanding the optimal timing, methods, and benefits of water replacement, shrimp farmers can enhance pond productivity and shrimp health. Regular monitoring, coupled with effective water change practices, ensures a sustainable and profitable shrimp farming operation.

Embrace these strategies, and let your shrimp ponds thrive!