Removing suspended solids with side-stream filtration
Rather than treating all cooling water at once, side-stream filters continuously clean a portion of cooling water, so that the entire water volume is filtered over the course of a day. Traditional side-stream filters are designed to remove suspended solids and silt from water, offering benefits that lead to improved operational efficiency.
In the 2012 paper, “Technical Evaluation of Side Stream Filtration for Cooling Towers,” the Federal Energy Management Program (FEMP) discusses the effectiveness of side-stream filters as solutions for combatting the primary water treatment concerns in cooling towers:
- Corrosion
- Scaling
- Fouling
- Microbiological Activity
By continuously removing solids, silt and organics, side-stream filters diminish fouling and biofouling in the system, which, in turn, reduces scaling and corrosion. However, cooling tower water treatment programs that utilize side-stream filters still require additional disinfection to control waterborne bacteria.
Controlling microbiological activity with chemical biocides
The FEMP report states that most mechanical filtration systems focus on the removal of suspended solids greater than 10 microns in size. But roughly 90 percent of suspended particles are smaller than that! Those smaller particles are typically bacteria, and traditional water treatment programs require oxidizing or chemical biocides for bacterial disinfection.
Those biocides require constant monitoring and can be harmful to handle and store. Often, they can create hazardous byproducts, and they contribute to corrosion of pipes and tubes in the HVAC system. That corrosion creates suspended particles that perpetuate the need for filtration and leads to increased maintenance and shortened equipment lifespans.

The Aqua-Stream™ high efficiency side-stream filter takes a revolutionary approach to cooling tower water treatment by filtering suspended particles and killing waterborne bacteria in a single step.
The high-efficiency sand filter removes particles down to 0.5 microns in size, but the magic really happens when bacteria comes into contact with the antimicrobial filter media (Pathex®). The EPA-registered filter media kills bacteria on contact, reducing the need for water treatment chemicals by as much as 90 percent.
The one-two punch of filtration and bacterial control improves operational efficiency by removing suspended particles and preventing the build-up of biofilm. Aqua-Stream can be sized to meet your flow rate needs, and its small footprint makes it ideal for settings where space is at a premium.
Why pay for two solutions, when you only need Aqua-Stream?
Contact us to see whether Aqua-Stream can solve your water treatment problems.
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