Defender® Regenerative Media Filters

Product Description

The Defender® Regenerative Media Filter is an award winning water filtration system capable of filtering down to 1 micron and requiring no backwash.  The Defender has rapidly replaced traditional sand filters as the premier choice for water filtration in a variety of applications.  It provides maximum performance, longevity and user friendliness while helping to reduce the global water footprint— an outcome that is good for the planet and our resources.

Designed with performance in mind.

Tank Construction

All vessels are conservatively engineered and manufactured with Flexsol 3000™ interior lining and include a 10 year fully rated warranty. The lining protects all wetted surfaces against corrosion to maximize the life expectancy of the vessel.


The Defender utilizes an intuitive graphic interface for controlling and monitoring all of its operations.  It features an animated graphic display, advanced communication & data logging, automated capabilities, remote monitoring capabilities, VFD connectivity, and UV connectivity.

Vacuum Transfer

At the push of a button, a self-contained, integrated pump quickly introduces dry media into the Defender® filter. This feature eliminates the mess and additional equipment required by wet, slurry designs.

Internal Hydraulics

Our underdrain manifold is engineered to achieve ideal distribution of influent flow. The generous open area serves to minimize turbulence and ensure superior “Flex Tube” coverage.

Lifting Davit

At some point it may be necessary to access the interior of the vessel. Our unique tank mounted davit permits easy access without remote lifting devices. The davit reduces the overall height requirement and saves valuable floor space.

Defender BumpIt’s all about the “Bump!”

The Defender® filter is programmed to automatically “bump” on a daily basis to regenerate the media coating of the “Flex Tubes.” This incredible benefit maximizes system performance while enhancing sustainability and conservation.


As the bump tire deflates (A), the tube sheet lowers to loosen the media and trapped debris. The re-inflation of the bump tire (B) raises the tube sheet and forces water into the “Flex Tubes”, gently expanding them to fully release all material. This bump cycle pulses ten times to ensure the entire cleansing process.

At the completion of the bump cycle, the Defender® will automatically pre-coat the “Flex Tubes” and re-commence the filter cycle. The “Bump” is a vital function in order to achieve superior filtration and to make the most out of every filter cycle.



Defender Assero™ Regenerative Media Filters Documents

  • Tech Data 1 (Defender_Assero_Technical_Data_Sheet_w_Schematic.pdf)

Defender® 27″ - 55″ Filter Documents


Defender® RMF System Controller

The Defender® utilizes an intuitive graphic interface for controlling and monitoring all of its operations. It features an animated graphic display, advanced communication & data logging, automated capabilities, remote monitoring capabilities, VFD connectivity, and UV connectivity.

Easy to Use

The RMF System Controller displays data through a 7” high resolution LCD and offers simple push button operation paired with on screen menus to make operation quick and easy. It also provides animated graphics with step-by step instructions on operating proceedures.

Advanced Control

The Defender RMF System Controller provides advanced control of bump and precoat cycles, pneumatic valves, recirculation pumps, vacuum transfer system, heater cool down delay, data logging and maintenance reminders. In addition, the system has the integrated ability to control Neptune Benson’s greendrive VFD system and ETS-UV systems providing additional flexibility and control of system operations.

Remote Monitoring and Control

The RMF System Controller features the ability to remotely manage operations. This cutting edge feature allows operators to keep track of system performance even when working on other tasks or while they are away from the facility. It provides remote monitoring, e-mail notifications of condition changes, and remote control of the system operations. Remote monitoring/operation can be done through any web browser or smart phone.

Data Logging and Exporting

The RMF System Controller continually logs data providing detailed information on water pressure stats, bump schedule, purge and more. Data can be viewed remotely and is exportable to .CSV formats for creating reports and working with the data.

Improve Efficiency

The data provided through the RMF System Controller can be used to analyze trends and modify operations to maximize effeciency. Analyze and identify peak usage, then automate or schedule bumping to insure optimal operation. Data logs can also be used to help troubleshoot issues by identifying operating issues.


Defender Goes Green

In a socio-economic climate promoting “green” building products and “sustainability”, Defender® is the earth-friendly solution for pristine pool water. Advantages include saving millions of gallons of water and waste; delivering superior pool water quality; saving on costly mechanical room space; and saving chemicals, fuel costs and energy. From Australia to Dubai and numerous US locations, aquatic professionals have selected and specified Defender®.


Leadership in Energy & Environmental Design

Developed by the US Green Building Council (USGBC) in 2000, a Green Building Rating System-has become the National Standard certifying design, construction & operations of green buildings.Projects (not products) are evaluated in five (5) areas:

• Sustainable Sites
• Water Efficiency
• Energy & Atmosphere
• Materials & Resources
• Indoor Environmental Quality
• Extra credit may earned for Innovation & Design

Number of credits earned determines the level of LEED Certification (four levels).

LEED projects are now in all 50 states and 41 countries.

Project types: New construction, Existing Buildings, Commercial Interiors, Core & Shell, Schools, Homes & Neighborhoods, Retail (Healthcare coming soon)

As of September 2007, there were 8,847 LEED registered projects in the US.

For more information on LEED, visit the U.S. Green Building Council at


“The Defender system was key to achieving over 1 million gallons of annual water savings for the LEED Platinum East Portland Community Center Aquatics Addition. And, its proven record for ease of maintenance was reassuring to our whole project team.”
— Eric Ridenour, LEED AP ND, NCARBAssociate, Project Architect, Urban Designer

Some Defender® success stories:


Cherokee County Aquatic Center
Cherokee County, GA.

“Cherokee County Aquatic Center immediately saved $135,000.00 off their Sewerage Permit Tab by selecting a Defender Filter over a Sand Filter. By upgrading to Defender, the new filter paid for itself before it was even installed! Now we are looking forward to enjoying the additional Water, Waste, and Energy Savings once the pool is commissioned, because as we know Defender eliminates over 90% of the backwash water associated with Sand Filter operation.”
— Bill Echols, AIA, Director of Capital Projects


Mt. Olympus Water & Theme Park
Poseidon’s Rage Surf Pool
Wisconsin Dells, WI

Grant awarded for the installation and use of energy efficient equipment. Awarded by Franklin Energy and Focus on Energy in the amount of $7956.00.

The grant was approved as a result of an efficient design associated with Defender® Filter Recirculation System. Due to the minimum amount of make-up water required to replace water lost to filter backwash, water heaters were not required to maintain pool water temperatures. The design of the Defender® Filter significantly reduced the motor horsepower required saving valuable energy dollars. Defender® Filter saved over 4.3 million gallons in this US largest surf pool in its first season.


Washtenaw Community College
Health & Fitness Center
Ann Arbor, MI

LEED registered building

Neptune-Benson’s Defender® Filters are used for the two pools at the 70,000 sq.ft. Health & Fitness Center at Washtenaw Community College, a LEED registered project opened 9/1/07.


WhiteWater World
Div. of DreamWorld
Gold Coast, Queensland, Australia

“One of the most water efficient water parks in the world.”
– Environmental Resources Management Australia (ERM)

Uses nine (9) Neptune-Benson Defender® Filter systems. Reduces annual waste by 98.7%. Saves over 22 million liters of water annually as compared to traditional sand filtration systems. The park’s science education lesson on Renewable Environment includes activities to discover why the use of Defender® Regenerative Media Filtration Systems is “the most important water saving strategy employed by WhiteWater World”.

Optional Features

Custom Models

Savings Analysis

Typical Wave Pool
  • 275,000 Gallons
  • 2 hour Turnover
  • 2,292 Gallons per Minute
Typical Annual Savings
  • 1,615,944 Gallons of Water per Annum
  • 63,846 Kwa of Energy per Annum
  • 30% Chemicals per Annum

National Average Payback Period:
12 Months

See annual savings using Defender®
Typical Competitive Pool
  • 400,000 Gallons
  • 6 hour Turnover
  • 1,333 Gallons per Minute
Typical Annual Savings
  • 503,784 Gallons of Water per Annum
  • 37,147 Kwa of Energy per Annum
  • 30% Chemicals per Annum

National Average Payback Period:
45 Months

See annual savings using Defender®
Typical Community Center Pool
  • 250,000 Gallons
  • 3 hour Turnover
  • 1,389 Gallons per Minute
Typical Annual Savings
  • 1,022,328 Gallons of Water per Annum
  • 38,695 Kwa of Energy per Annum
  • 30% Chemicals per Annum

National Average Payback Period:
25 Months

See annual savings using Defender®
Typical Lazy River
  • 500,000 Gallons
  • 2 hour Turnover
  • 4,167 Gallons per Minute
Typical Annual Savings
  • 3,231,888 Gallons of Water per Annum
  • 116,084 Kwa of Energy per Annum
  • 30% Chemicals per Annum

National Average Payback Period:
12 Months

See annual savings using Defender®
Typical YMCA Lap Pool
  • 150,000 Gallons
  • 4 hour Turnover
  • 625 Gallons per Minute
Typical Annual Savings
  • 367,950 Gallons of Water per Annum
  • 17,413 Kwa of Energy per Annum
  • 30% Chemicals per Annum

National Average Payback Period:
52 Months

See annual savings using Defender®
Typical Therapeutic & Wellness Pool
  • 50,000 Gallons
  • 2 hour Turnover
  • 417 Gallons per Minute
Typical Annual Savings
  • 331,290 Gallons of Water per Annum
  • 11,608 Kwa of Energy per Annum
  • 30% Chemicals per Annum

National Average Payback Period:
51 Months

See annual savings using Defender®



Water & Waste Savings

The Defender significantly eliminates the amount of backwash water associated with sand filter operation. Instead of backwashing, the Defender is programmed to automatically “bump” to regenerate the fine-grade perlite media for a fresh start. Eventually the filter will become saturated with trapped dirt and will require a quick and easy media discharge and replacement. Depending on bather load, the life cycle of the media averages around every four weeks.

Backwash Water Consumption

Filter Type Filter Area
(sq ft)
Backwash Rate
(gpm/sq ft)
Backwash Volume
Annual Volume
(4) 4884SHFFG-6
126.8 11.8 9510 gal
3x / week
(1) SP-49-48-1548
1211 1.2 1230 gal
1x / 4 weeks
Annual Water & Waste Savings:
1.468,800 gallons

Energy & Chemicals Savings

The dramatic reduction of backwash waste directly translates to savings in make-up water along with the chemicals and fuel for re-heating. Consider the cost of chemically treating 1.4 million gallons and the BTU’s required to heat this volume from 50 degrees (10 °C) to 80 degrees Fahrenheit (27 °C).

It is also important to note that the improved water quality generated by Defender’s ability to remove finer particles will also save on general chemical consumption.

Estimated annual savings ranges from $42,000 to $52,000 depending on local fuel costs for oil, gas or electricity. Based on the Backwash Water Consumption of a typical waterpark attraction with a 2000 GPM (454m3 /hr) recirculation rate.

Energy Savings

Construction Savings

More savings are derived from the smaller construction footprint for Defender® filter.

This results in as little as one-fourth to one-sixth of the space required by an equivalently sized sand system, saving installation and rigging time. The lesser operating weight of the Defender® filter reduces the extent to which the floor slab must be engineered. With building costs at an estimated $75 to $150 per square foot, selecting Defender® could generate construction savings in the tens of thousands of dollars.


Additional Construction Benefits:

  • No backwash holding tank
  • Small waste line to sewer
  • Local backwash to waste flow rate restrictions are no longer an issue
  • Operating weight may be as little as 10% of a similar sized sand filter

Power Savings

Defender® reduces head loss (vs. sand) to saves motor horsepower operational cost.

Starting differential pressures for a high-rate sand filter, depending on the media, could range from 4 to 6 psi (27.6 kpa to 41.4 kpa). In contrast, the starting differential of the Defender® is approximately 1 psi (6.9 kpa).

Converting this to head represents savings of nearly 12 feet (3.65m) total dynamic head, or TDH, which translates to horsepower and energy savings. In most cases, the pump motor required for Defender® filter recirculation is smaller than a sand filter. Utilizing a 25hp motor instead of a 30hp unit would result in electricity savings of $3,000 per year.

In waterparks with multiple attractions, the savings would be much more.

Defender Technology Delivers Huge Energy Savings

This graph illustrates the actual operating pressures of High Rate Sand Filters compared to Defender Regenerative Media Filters.

The RED line represents the fluctuations in PSI for High Rate Sand Filters throughout one complete filter cycle (3 days). The BLUE line indicates the PSI differential for Defender Filters over a similar cycle (21 days).

As a result of the “Bump” cycle, the Defender operates at a dramatically lower head pressure and vastly reduces energy costs. The GREEN shaded area represents the level of lower head requirements which translates directly to dollars saved.“Defender Technology Delivers Huge Energy Savings”

Power Savings Chart

A High Rate Sand Filter, designed at 12 GPM/SF will typically start with a 5 PSI pressure differential, when clean. A pressure differential increase of 10-12 PSI occurs every 3 days, requiring backwashing.

A Defender Filter, designed at 1.3 GPM/SF, will typically start with a 1 PSI pressure differential with new media. Daily pressure differential increase will be 0.25 PSI after bumping. A typical 21 day cycle has yielded a 5.5 PSI pressure differential increase.

All data is provided by Great Wolf Resorts based on actual results of filter systems they operate at various facilities in North America.

Water Quality


See how big a micron is

The Defender® filter will remove particles down to 1 micron. With the growing concerns about waterborne illnesses (WBI) such as cryptosporidiosis, the smaller the particle removal the better. The Defender® filter is especially effective on pools with heavy bather loads because of the increased filter area and dirt holding capacity.

Defender® filter will also retard the increase in turbidity. A major contributor to turbidity in pool water is the treatment chemicals, especially sodium hypochlorite. The improved filtration, along with the reduction of make-up water, cuts the chemical requirements and the associated turbidity buildup.

Findings from a recent study by the University of North Carolina on cryptosporidium and particle removal from swimming pool water indicate:

• Precoat Filtration with both DE and perlite outperformed cartridge and sand filtration by a wide margin
Single pass testing resulted in crypto removal of 99.9% using perlite media
• When testing 1-micron microsphere removal, perlite performed at 56.5% versus 20.2% for sand



Features & Benefits



Test Drive the Defender RMF

This simulation demonstrates the actual steps for the complete operation of the Defender® Filter. You will see how simply the RMF Programmer functions with the automated features of the system.