The Defender

The Defender® filter is an earth friendly solution for pristine pool water and it continues to have a marked impact on the global water footprint. This industry leading filter will give you maximum performance, longevity and user friendliness — an outcome that is good for the planet and our resources.


Product Description

The Defender® filter is an earth friendly solution for pristine pool water and it continues to have a marked impact on the global water footprint. This industry leading filter will give you maximum performance, longevity and user friendliness — 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 Model RMF programmer manages automation for all filter cycles including regeneration (bump), maintenance mode, and media transfer. Easily interfaces with chemical controllers, heaters, and variable frequency drives. Saves labor and maximizes operational security.

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.

AB 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.


Water & Waste Savings The Defender® filter virtually eliminates the tremendous amount of backwash water associated with sand filter operation. Instead of reverse flushing, as with a sand filter, Defender® simply discharges the spent media directly to waste and is recharged from time to time. The following chart illustrates the Backwash Water Consumption of a typical indoor waterpark attraction with a 2000 GPM (454 m3/ hr) recirculation rate. The annual water savings in excess of 2.2 million gallons (8328 m3) is complemented by associated costs related to sewer expenses, chemicals, heating, power and labor.

Backwash Water Consumption

Filter Type Filter Area (SQ FT) Backwash Rate Backwash Duration Backwash Frequency (PER YEAR) Total Volume (GAL)
Sand 16712 GPM/SQ FT (15.5m2) (2.7m3/hr) 15 GPM/SQ FT (3m3/hr) 5 minutes 182 2,279,550 (8679m3)
Defender® 1708 (158.7m2) 841 GAL (tank volume) (3.18m3) 2 times (including rinse) 12 20,184 (76.4m3)

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 2.2 million gallons (8328 m3) 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 save motor horsepower operati

onal 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. TheRED 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


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



Savings Analysis

  • 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


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


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


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


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


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


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



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.