As December 2025 approaches, weather conditions across Indonesia are expected to remain largely dominated by high rainfall.  

According to data from the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG), rainfall distribution is projected to fall mostly within the moderate (50.50%) and high (48.33%) categories, with 0.87% classified as very high, and only 0.29% considered low. 

This distribution shows that rainfall toward the end of the year is not only more frequent, but also potentially more intense.  

For shrimp farming operations, this is not something to take lightly. Heavy rain can rapidly alter pond water conditions, often in ways that are difficult to predict or control. 

Understanding the impact of rainwater on shrimp ponds, along with proper shrimp pond preparation, is essential to keeping pond conditions stable, minimizing stress on shrimp, and maintaining performance through the end of the culture cycle. 

The Impact of Rainwater on Shrimp Ponds During the Rainy Season 

High rainfall does more than increase water volume—it also brings chemical and biological changes that can disrupt the balance of the pond ecosystem. 

Diluted Water and Mineral Imbalance 

Rainwater entering the pond dilutes the water column. This condition is often followed by a drop in salinity and essential minerals, which can interfere with shrimp osmoregulation. In addition, shifts in nitrogen balance may increase the proportion of toxic ammonia (NH₃), posing further risks to shrimp health. 

Shrimp Floating Due to pH Drops and Toxic Gases 

In ponds with acidic soil, deep pond structures, or long operational histories, heavy rainfall can cause a sudden drop in pH. This situation may trigger the release of toxic hydrogen sulfide (H₂S) gas from the pond bottom, weakening shrimp and causing them to float at the surface. 

Overly Clear Water and Phytoplankton Disruption 

Changes in alkalinity and CO₂ concentration following rainfall can lead to a decline in phytoplankton populations. When water becomes too clear, excessive light penetration can disrupt ecosystem balance and encourage the growth of filamentous algae. 

Increased Turbidity and Organic Load 

Rainwater runoff carries soil particles and organic matter from surrounding areas into the pond. As a result, turbidity increases, biological oxygen demand (BOD) rises, and dissolved oxygen levels may drop—especially in high-density ponds. 

Soft Shell and Molting Issues 

Sudden environmental changes, combined with mineral imbalance, often disrupt the molting process. Shrimp become more susceptible to soft-shell conditions and may experience suboptimal growth. 

Water Quality Parameters to Monitor During the Rainy Season 

During the rainy season, changes in pond water quality can occur rapidly and are not always visible to the naked eye. For this reason, key parameters should be monitored more frequently as part of shrimp pond preparation. 

Important parameters to watch include: 

  • Salinity 
    Rainfall can cause sudden drops in salinity. Extreme fluctuations may increase stress and weaken shrimp resistance. 
  • pH and Alkalinity 
    Rainwater tends to be acidic and can lower both pH and alkalinity, increasing the risk of toxic gas release from the pond bottom. 
  • Ammonia (NH₃/NH₄⁺) 
    Water dilution and rising organic matter can elevate toxic ammonia levels, particularly after heavy rainfall. 
  • Turbidity and Total Suspended Solids (TSS) 
    Runoff introduces soil particles and organic materials that interfere with light penetration and phytoplankton photosynthesis. 
  • Water Clarity and Phytoplankton Condition 
    Changes in water color and transparency can serve as early indicators of ecosystem imbalance. 

By understanding and closely monitoring these parameters, farmers can take corrective action more quickly before pond conditions deteriorate. 

Preparing Shrimp Ponds for the Rainy Season 

To help shrimp farmers navigate the challenges of the rainy season, Bahtera Adi Jaya introduces the Rainy Season Survival Pack—an integrated set of solutions designed to maintain stable pond water quality during periods of high rainfall. 

MinGro: Rapid Mineral Booster 

MinGro helps restore essential minerals lost due to water dilution and supports shrimp osmoregulation and molting. 

  • Light rain: 3 kg/ha 
  • Moderate rain: 6 kg/ha 
  • Heavy rain: 12 kg/ha within the first 3 hours, followed by 6 kg/ha every 3 hours 

AlkaSet: Alkalinity & pH Stabilizer 

AlkaSet helps maintain alkalinity and stabilize pond pH after heavy rainfall. 

  • Dosage: 10 kg/ha 

FytoGro: Phytoplankton Growth Promoter 

FytoGro accelerates the recovery of phytoplankton populations to maintain balanced light and nutrient conditions. 

  • Light rain: 1,5 kg/ha 
  • Moderate rain: 3 kg/ha 
  • Heavy rain: 6 kg/ha, followed by 3 kg/ha every 3 hours  

FytoShade: Smart Light Filter 

When water becomes overly clear, FytoShade helps regulate light penetration to support more stable phytoplankton growth. 

  • Dosage: 250 g/ha 

SoilGro: Pond Bottom & Organic Matter Manager 

SoilGro uses probiotics to break down sludge and organic residues, improving pond bottom conditions. 

  • Dosage: 250–500 g/ha 

AlphaSep: Viral Load Control During Culture 

AlphaSep supports viral load control, which often becomes more challenging after rainfall. 

  • Dosage: 0,2 ppm 

AmmoTrap: Instant Ammonia Control 

AmmoTrap provides rapid reduction of toxic ammonia levels following rain. 

  • Seawater ponds: 0,3 ppm 
  • Freshwater ponds: 0,2 ppm 

The rainy season presents a demanding period for shrimp farming, particularly when high rainfall occurs repeatedly. By understanding the impact of rainwater on shrimp ponds, monitoring key water quality parameters, and implementing proper pond preparation, the risks of stress and reduced productivity can be minimized. 

Through the Rainy Season Survival Pack, Bahtera Adi Jaya aims to support shrimp farmers in maintaining water quality, shrimp health, and overall pond productivity throughout the rainy season. Find your shrimp pond solutions with Bahtera here.