Magnesium chloride (MgCl2) is commonly used in aquaculture for various purposes. Here are some of the applications of magnesium chloride in aquaculture:

1. Water quality: Magnesium chloride can be used to improve water quality in aquaculture ponds. It helps to increase the hardness and alkalinity of the water, which can promote healthy fish growth.

2. Stress reduction: Magnesium chloride can help to reduce stress in fish. It has a calming effect on fish and can help to reduce the negative effects of stress, such as reduced immune function and increased susceptibility to disease.

3. pH control: Magnesium chloride can be used to control the pH of water in aquaculture ponds. It can help to buffer the water against changes in pH, which can be beneficial for fish health.

4. Disease prevention: Magnesium chloride can be used to prevent certain diseases in fish. It has been shown to have antimicrobial properties and can help to prevent the growth of harmful bacteria and fungi in aquaculture ponds.

5. Nutrient supplementation: Magnesium chloride can be used to supplement the diet of fish with essential nutrients. It is a source of magnesium and chloride ons, which are important for fish health and growth.