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Nitrite, an intermediate compound in the oxidation of ammonia nitrogen to nitrate by nitrifying bacteria in soil and water, is considerably more toxic than nitrate. Exposure to nitrite causes gill lesions and edema in the skeletal muscles of fish, and also affects respiration. 

The preventive use of common salt (sodium chloride) by commercial producers of freshwater fishes has many benefits, including helping with the routine prevention of losses due to diseases, stress and mishandling during transport, harvesting, grading, counting, weighing and induced spawning. 

El uso preventivo de sal común (cloruro de sodio) por los productores comerciales de peces de agua dulce tiene muchos beneficios, incluyendo ayudar a la prevención de rutina de pérdidas debidas a las enfermedades, el estrés y el mal manejo durante el transporte, recolección, clasificación, conteo, pesaje y desove inducido. 

Total alkalinity is an important variable in water for aquaculture systems, and its concentration frequently fluctuates over time in many culture systems. 

Intensification of pond aquaculture involves the use of commercial fertilizers such as urea and triple superphosphate to stimulate phytoplankton blooms. There is no objective way of determining the ideal fertilization rate for an individual pond. 

Aerators, especially paddlewheels, are often used to mix the water and address oxygen stratification in ponds. However, most aerators do not provide the most efficient and power-conscious service. Due to thermal and oxygen stratification in ponds, the efficiency of paddlewheel aerators is low, and other present-day aerators have other problems. Emerging designs should better address effective mixing and aerating of pond water. 

The ideal pH for most aquaculture species is between 6.0 and 8.5. Lower pH values may result in decreased growth and survival, and greater susceptibility to disease. pH typically is lowest in the early morning, increases during the afternoon and declines at night. 

This study compared water temperature and water loss by evaporation in control ponds and in ponds aerated with surface aerators at four different aeration rates. Increased aeration rate increases the evaporation rate, which in turn lowers water temperature. 

Oxidants are used in aquaculture as disinfectants or to enhance water quality. Hydrogen peroxide and sodium carbonate peroxyhydrate can be sources of dissolved oxygen in emergency situations where mechanical aeration is not possible. 

Este estudio comparó la temperatura del agua y la pérdida de agua por evaporación en estanques de control y en estanques aireados con aireadores de superficie a cuatro velocidades de aireación diferentes. El aumento de la tasa de aireación aumenta la tasa de evaporación, que a su vez reduce la temperatura del agua. 

The traditional way of destroying organisms in pond bottoms is thorough dry-out for a week or longer. Fish toxicants and liming can kill unwanted parasites. 

Troublesome turbidity in aquaculture pond water often results from clay or fine silt particles that remain suspended due to turbulence or sedimentation. 

At the Guatemalan Aquaculture Symposium in Antigua, the focus was shrimp farming in the region: production, nutrition, health management and markets. 

En el Simposio de Acuacultura de Guatemala en Antigua, el enfoque fue el cultivo de camarón en la región: producción, nutrición, gestión de la salud y mercados. 

Those interested in using groundwater for aquaculture should perform a thorough chemical analysis of the water. Several problems related to groundwater use in hatcheries and holding or transport vessels can be alleviated by degassing or aeration. 

Alkalinity and acidity in pond water and soil interact and can result in unhealthy culture conditions. Ion exchange occurs between soil and water until an equilibrium is reached.