Water quality is a critical factor in aquaculture, as the water body must maintain “vitality” and “nutrient richness” to support fish growth. However, stable weather fluctuations and increased aquaculture density often lead to various issues in ponds—for example, abnormalities in common water quality indicators such as nitrite, ammonia nitrogen, and dissolved oxygen. This article provides a brief overview of the causes of such abnormalities and corresponding countermeasures.

1.Hazards of Abnormal Water Quality Indicators  

1.1 Ammonia Nitrogen Exceedance  

Elevated ammonia nitrogen levels can cause acute poisoning in shrimp and crabs, leading to muscle spasms and, in severe cases, mortality. Primary contributors include excreta from aquatic organisms and residual fertilizers.

1.2 Nitrite Exceedance

Excessive nitrite is highly toxic, damaging the liver of fish, shrimp, and crabs, and may also result in mortality. Key causes include high aquaculture density and excessive feed input, which increase the accumulation of harmful substances in aquatic organism excreta.

1.3 Low Dissolved Oxygen (DO)

Insufficient DO induces hypoxia in fish; if left unaddressed, it can cause mass mortality of fish and shrimp. DO levels are primarily influenced by weather and temperature.

2.Role of Water Quality Monitoring in Aquaculture  

Water quality monitoring serves to continuously track whether all water quality indicators meet established standards, enabling timely identification and resolution of potential issues.

3.Detection and Remediation of Abnormal Indicators  

Abnormalities in water quality indicators can be detected using Water Quality Analyzers, which allow targeted testing of specific indicators based on operational needs to verify compliance with standards. Remediation strategies should be tailored to test results:

• Algae and Bacteria Application: Algae absorb ammonia nitrogen and nitrite as nutrients, reducing their concentrations to standard levels. Bacteria decompose organic nitrogen into inorganic nitrogen, which is also assimilable by algae.
• DO Enhancement:For low DO, address DO sources and consumption. Reducing organic matter decomposition (a major DO consumer) effectively increases DO levels in the pond.