Alum has been a long-standing tool in our toolbox of lake and pond management solutions—and is a particular favorite of professionals who strive to use only sustainable maintenance practices. Alum (also known as Aluminum Sulfate) is used in a wide array of industries and applications such as drinking water management and wastewater treatments. In the lake and pond management industry, Alum is used to reset the chemical balance of aquatic environments to improve water quality. When water quality is enhanced, it creates an environment that is less hospitable to algae, nuisance weeds, and toxic cyanobacteria.

Alum is applied to lakes and ponds as a white, powdery substance. As the Alum mixes into the water column, it binds with free-reactive nutrients, creating a cloudy trail behind the boat or a specially-designed application barge. After a short period of time, the particles sink to the bottom where they will remain inactive. Alum is considered very safe when applied by a professional and provides fast-acting results that can last for years. Almost immediately after an application is complete, the water column will become more clear. Over the course of days and weeks, the water quality improves.

Alum is not the only natural substance that removes nutrients in the water column. Solutions like Phoslock and EuroSORB work similarly to target Phosphorus.

Phoslock is a lanthanum-modified clay that binds with excess phosphorus, chemically changing its composition so that they can no longer support weeds and algae. EutroSORB, on the other hand, is a filtration technology that captures nutrients in the water column. It is particularly effective in waterbodies with significant movement and mixing, such as stormwater ponds, streams, and canals. Once the filter is fully saturated with phosphorus, it is pulled from the water for disposal. In some cases, experts may also choose to use an aqueous form of EutroSORB that can be poured or sprayed on the surface, or applied via subsurface injection.