What chemical is commonly used to kill algae in lakes?

Copper sulfate is a widely used chemical for effectively controlling algae in lakes and other water bodies. It works as an algaecide by releasing copper ions when dissolved in water, which disrupt the cellular functions of algae, leading to their death. This method is particularly effective against a variety of freshwater algae species and is favored in aquatic environments due to its targeted action.

Copper sulfate is often chosen for its efficiency and relatively low toxicity to aquatic organisms when used at recommended dosages. It’s important, however, to monitor the application rates to avoid potential toxicity to fish and other aquatic life.

The other chemicals listed are used for different purposes. Sodium bicarbonate is typically used to adjust pH and does not have significant algaecidal properties. Ferric chloride is generally used as a coagulant in water treatment processes rather than for algae control. Alum is another coagulant that helps remove particulates and may have some effect on algae, but it is primarily used to improve water clarity rather than specifically target algae growth.