Alum Applications


Is alum natural and safe for restoring water quality?

A lake or pond with poor water quality conditions is practically useless to homeowners associations, golf courses, municipalities, and private property owners. In fact, if the right steps are not taken to correct the issues early on, it can become a significant headache and money pit for the stakeholders in charge of its care. The primary source of most water quality problems is nutrient pollution. While beneficial and critically necessary to support aquatic environments, excess nutrients like phosphorus can wreak havoc by disturbing the delicate balance of the ecosystem. Implementing sustainable solutions as soon as possible will help restore healthy conditions and avoid unnecessary muck development, nuisance plant and algae growth, bad odors, flooding, erosion, and other complications.

Determining The Best Solution for Your Waterbody

Finding the right management solution depends on many factors. Your lake management professional will begin by collecting water quality data and analyzing it in a laboratory setting. This process reveals a wealth of important knowledge about your water resources that will inform next steps. Depending on the size, depth, pH, water currents, and problems that your waterbody is experiencing, such as toxic cyanobacteria (blue-green algae), experts may recommend nutrient remediation services to improve water quality. 

Three natural, eco-friendly products can be used to target excess nutrients—Phoslock, EutroSORB, and Alum (Aluminum Sulfate). They each accomplish this in different ways.

Nutrient Remediation Solutions

Phoslock is a type of lanthanum-modified clay that binds with free-reactive phosphorus in the water column, converting it to forms that are unable to fuel organic growth. Alum works similarly by binding with phosphorus and other nutrients in the water column to form larger particles that sink to the bottom of the waterbody where they become inactive. EutroSORB is a filtration technology that captures nutrients in moving water. Once saturated, the filter is physically disposed of. Eurosorb can also be used in an aqueous form that can be sprayed, poured, or injected into a waterbody. Both of these solutions enhance water quality by reducing excess nutrients. When water quality is more balanced, it becomes difficult for water quality issues like algae and aquatic weeds to develop.

Understanding Alum Applications for Water Quality Restoration

Stakeholders often have many questions about nutrient remediation products, particularly Alum. How does it affect aquatic habitats and beneficial organisms? Is it safe to add to drinking water or lakes and ponds used for recreation? 

Alum is a natural, well-studied product that has been used for more than 200 years for wastewater treatments and drinking water clarification. Over the last 50 years, it has become an important tool for the sustainable maintenance of recreational lakes and ponds. When properly applied by licensed professionals, Alum and considered very safe. In fact, residents can swim, kayak, and enjoy the water while applications are taking place.

Though Alum is generally risk-free, some problems can occur if stakeholders choose to do the work themselves. In addition to lacking the necessary equipment, the inexperienced are rarely equipped with the knowledge and personal protective equipment (PPE) to handle the substance at concentrated levels. Professionals also have access to specialized boats, barges, tanks, booms, and tools to ensure the Alum is applied consistently across the waterbody. These tools include a pH stabilizer that is applied simultaneously to limit water chemistry from becoming too imbalanced. This helps prevent fish kills and disturbances to other aquatic life.

The Importance of Collecting Data

In addition to the necessary products and equipment, experts have the accessories and in-house laboratories to conduct comprehensive data collection – including water quality testing, sediment studies, and bathymetric mapping – before and after the project. Data serves as the backbone of any job. Knowledge of phosphorus levels and the source of the nutrients helps estimate the amount of product used, the length and frequency of treatments, and projected costs. Upon completion of a project, data helps demonstrate the overall impact of the Alum treatment.

Preventing Nutrient Loading

Alum is a highly safe and effective option in our toolbox of natural solutions, but it alone cannot solve all of your lake or pond problems. For example, nutrients will continue to enter your waterbody in the form of animal waste, fertilizers, lawn clippings, plant matter, trash, motor oil, and eroded sediment that are picked up during rainstorms. Stakeholders can take steps to inhibit these pollutants and protect the investment that they have made in the Alum treatment.

The introduction of a beneficial vegetative buffer is a great place to start. Planting native, beneficial plant species around the perimeter of the waterbody will help filter out the nutrients found in stormwater runoff, contain soil in place, and create a more beautiful backdrop along the shoreline. If erosion has already become a chronic issue, professionals may recommend a full restoration of the lake or pond bank. Bioengineered shoreline technologies make it possible to anchor loose sediment in place while blending seamlessly into the surrounding landscape, increasing overall beauty and safety. 

Implementing Proactive Solutions

To further support the health of the aquatic environment, stakeholders can consider other natural solutions like beneficial bacteria applications to eliminate bottom muck and bad odors, fountains and aeration to enhance the flow and chemistry of the water column, and mechanical hydro-raking to physically increase the depth and volume of the waterbody. Each of these solutions, including Alum, plays an important role in a long-term maintenance plan, which is custom-designed to promote excellent water health on an annual basis. Learn how a SOL Pro Annual Management Plan can help you create happy experiences and memories in and around your waterbody for years to come.

Improve Water Quality with Nutrient Remediation

Contact Us to Enhance Your Water Quality

Call us at 866-781-8904 or complete the form below to get connected with an aquatic management expert.

SOLitude Lake Management is a nationwide environmental firm committed to providing sustainable solutions that improve water quality, enhance beauty and preserve natural resources.

SOLitude’s team of aquatic scientists specializes in the development and execution of customized lake, stormwater pond, wetland and fisheries management programs. Services include water quality testing and restoration, algae and aquatic weed control, installation and maintenance of fountains and aeration systems, shoreline erosion control, muck and sediment removal and invasive species management. SOLitude partners with homeowners associations, golf courses, private landowners, businesses and municipalities. SOLitude Lake Management is part of Rentokil, a leading business services company, operating across the United States, Canada and Puerto Rico.

For more information, visit SOLitude Lake Management at, and connect on FacebookLinkedIn and Twitter.

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