Outback Gravity-Powered Systems - FAQs


 Q.  Does the Outback provide enough water for a family of 4+?

A. Yes, both the mini and standard Outback Gravity-PoweredTM Systems can produce an adequate amount of drinking water for a single user or a family or group of 4 people or more. 

Q.  How much water does the Outback Gravity-PoweredTM produce in a 24 hour period?

 A.  The standard Outback has a daily production rate of up 24 gallons per day. The Outback-Plus has a daily production rate of 12 gallons per day.

 Q.   How many types and sizes of Outback Gravity-PoweredTM systems are available?

A.  There are currently four Outback Gravity-PoweredTM models available. The mini Outback (OB-22FF), Outback (OB-25FF), mini Outback-Plus(OB-22NF) and the Outback-Plus(OB-25NF). We also offer DIY kitS for those who what to create their own system.

Q.  What Filters come with the standard Outback (FF) systems?

A.  The standard Outback Systems  (designated as "FF" systems) contain one filter net, one sleeve, two pre-filters and one multimedia post filter. 

Q.  What filters come with the Outback-Plus (NF) systems?

A.  Outback-Plus systems (designated as "NF" systems) contain one filter net, one sleeve, one Nano filter and one multimedia post filter.

Q.  Can you buy extra filters for the Outback and Outback-Plus Systems?

A.  Yes, extra filters are available for sale for all four Outback systems.

Q.  Do the Outback Systems come with an instruction manual?

A.  Yes, all Outback Gravity-PoweredTM Systems and DIY kits come with the instructions necessary about how to assemble and use the product.

Q.  Is it difficult to assemble the Outback system?

A.  No, It takes less than five minutes, from start to finish, to complete the Outback Gravity System assembly process.

Q.  What type of water source can I use in an Outback Gravity-PoweredTM System?

A.  It is always best to use water from a fresh water source. Typical water supplies used with the Outback Gravity Systems are streams, creeks, rivers, ponds and lakes. Additional water sources may be rain water collection, water heaters, swimming pools, spas, fresh water from the toilet and untreated stored water.

Q.  Is the Outback portable?

A. Y es, it is as simple as grabbing the handle and going. This was an important part of the design in the event one was forced to leave their home. The Outback can also act as a source of additional storage for such items as insurance papers, extra medication, power bars. flash light, matches etc.

Q.  What makes the Outback Gravity-PoweredTM Systemdifferent from other forms of water treatment systems?

A.  Both its effectiveness and its true portability differentiate the Outback from other 'emergency' systems. From conception, our goal was to design a utilitarian product that would function reliably in the event of an emergency or when used in undeveloped locations. The Outback was not designed to be an 'attractive kitchen appliance' - but rather a durable, portable, affordable, simple water purification system -- effective in the removal of water borne micro organisms and chemicals. Many of the water treatment products and systems currently sold as "Emergency Preparedness Systems" or as systems to be used in undeveloped areas, were never intended for such use and/or work poorly in those applications.

Q.  Does the water produced by the Outback taste good?

A.  Yes, with the high capacity multimedia Outback post filters any 'off' tastes or odors are removed before the water enters the lower chamber, ensuring the water is clean and has a pleasant taste.

Q.  Can I get a system for my home that uses the same type of filtration as the Outback systems?

A.  You can now. OutbackWater is using the latest Nano technology in filters and filtering systems that work with standard household pressure, as well as filters that can handle flow rates of up to 3-4 gallons per minute. In many cases, if you already have a filtration system in your home there is no need to replace it. You can simply change out your old filters with the newest filter technology offered by OutbackWater. Contact us for more information.

Q.  Does the Outback come with an instruction manual?

A.  Yes, all Outback Systems and DIY kits come with the necessary instructions on how to assemble and use the product.


Q.  How does the Outback work?

A.  Outback produces purified water through simple gravity power. Untreated water is poured into the upper chamber (bucket) and gravity draws the water through four stages of filtration & purification into the lower chamber (bucket).

Q.  How many stages of filtration does the Outback have and what are they?

A.  There are four very separate and very important stages of filtration used in the Outback systems. Stage 1 is the pre-filter net, fits over the top of the upper bucket. It removes any large particles and debris from the water. Stage 2 is the pre-filter sleeve -- a soft filter that fits over the filter in the upper bucket. This sleeve removes finer particles such as sand and sediment. Stage 3 is the pleated filter installed in the upper bucket. This filter removes the water borne microorganisms such as bacteria, cysts and (in the case of the Outback Plus systems) viruses. Stage 4 is the solid filter installed in the lower bucket. This filter removes a multitude of chemicals, pesticides, organic contaminants as well as odors and "off" tastes.

Q.  How do I know when it is time to replace the Outback pre filter and multimedia filter?

A.   A reduction in flow is generally the easiest method of determining when the filters need to be changed. Based on years of field trials it is recommended that the RF05-7 and NF-7 filters (installed in the upper bucket) are replaced every 6 months or when a noticeable reduction in flow takes place. The post filters should be replaced after 12 months or at their rated capacity - whichever comes first. The RM200 is rated for 1200 gallons and the RM300 for 1800 gallons.. The pre-filter net and sleeve can be washed and reused and by keeping both items clean or replacing them on a regular basis the recommendation should work for any standard user.  Using the clearest possible water source, a settling bucket and keeping the pre-filter sleeve clean is helpful in prolonging the useful life of the filter.

Q.  What is the "Nano filtration" used in the Outback Plus system? How does it work?

A.  The most recent water treatment filter media technology used by ESP for the removal of microorganisms such as bacteria, cysts, endotoxins and virus is Nano filtration - a method of capturing microorganisms with an electrostatic charge. This is where a fibrous filter media carries an electrostatic charge and particles carrying an opposite charge are attracted and adsorbed. Most particles including pathogens are electronegative in water, so an electropositive filter media is highly effective in attracting and holding the electronegative particles. The fibrous filter media consists of small filters, two Nanometers in diameter, which are dispersed throughout a cellulose, polymetric, microglass fiber matrix resulting in a 2 micron pore size filter media. Since the electro-positive charge of the material provides the mechanism to remove the waterborne pathogens a single layer of the media is able to retain greater than 99% of 0.025 micron size MS2 virus providing an absolute rating of 0.03 microns. The fibrous filter media is pleated to produce a high surface area filter, suitable for high flow rates with minimal pressure drop. It can also be formed into a multilayer depth filter capable of filtering virus size particles to greater than a 6 (LTR) log retention value or >99.9999%.

 Q.  What type of material are the Outback buckets made from?

A.  The Outback buckets are made from food grade High Density Polyethylene plastic (HDPE), which has several applications including food packaging such as milk and snack packs.

 Q.  What is the difference between a cyst, bacteria and virus?

A.  The difference between the three most common pathogenic (capable of causing disease) microorganisms are:

Bacteria: single celled organisms which lack well defined nuclear membranes and other specialized functional cell parts and reproduce by cell division or spores. Bacteria may be free living organisms or parasites.bacteria cells range from 1 – 10 micron in length and 0.2 – 1 micron in width.

Cyst: a capsule or protective sac produced about themselves by many protozoan, as well as some bacteria and algae as preparation for entering a resting or a specialized reproductive stage. Generally 2 - 50 micron in diameter.

Virus: a parasitic infectious microbe, composed almost entirely of nucleic acid, which can cause disease(s) in humans. Viruses can only reproduce within living cells. They are 0.004 – 0.1 microns in size about 100 times smaller than bacteria.

 Q.  What is a settling bucket and when should I use one?

A.  A settling bucket is recommended when the untreated water supply contains a large amount of fine silt and sand.   By collecting the untreated water in a bucket and then allowing it to 'sit' for a period of time, sediment, dirt and fine particles will settle to bottom of the bucket. The clear water can then be poured into the Outback System. This will minimize the amount of debris that is poured into the Outback system and help protect the Outback filter from premature clogging or 'exhaustion'.


 Q.  What makes a water system a 'purifier' instead of a 'filtration system'?

A.  Proven performance! To be considered a 'purifier' a water treatment system or device must effectively remove microorganisms to the EPA standard of 99.9999 % for bacteria, 99.9% for cysts and 99.99% for virus.

 Q.  Do any of the Outback Systems qualify as purifiers?

A.  Yes, both the Mini-Outback Plus(OB-22NF) and the full sized Outback Plus(OB-25NF) systems meet EPA's purifier standard using the NF7 filter (Nano filtration). The Mini-Outback (OB-22FF) and the standard Outback (OB-25FF) can function as purifiers but require the assistance of either a chlorine or iodine additive to meet that standard.

 Q.  Do the Outback Systems effectively remove bacteria?

A. Yes, all of the Outback Systems effectively remove bacteria at a rate of greater than 99%. The Outback Plus removes bacteria at a rate of greater than 99.9999%.

 Q.  Do the Outback Systems effectively remove cysts?

A.  Yes, all of the Outback Systems effectively remove cysts at a rate of greater than 99.99% -- exceeding EPA standards.

 Q.  Do the Outback Systems effectively remove virus?

A.  Yes, the Outback Plus systems (OB-22NF and OB-25NF) use "Nano Filteration" technology to effectively remove virus at a rate of greater than 99.99%. The standard Outback Systems (OB-22FF and OB-25FF) will only remove virus with the assistance of chlorine or an iodine additive.

 Q.  Do the Outback Systems remove chemical contamination?

A.  Yes, all of the Outback Systems use a mixed blend combination of carbon (multimedia) that is formulated to remove a long list of organic contaminates.

 Q.  Will the Outback system remove salt from the water?

A.  No, the Outback will not remove salt from the water.

 Q.  What does it mean when it says a filter is 'bacteriostatic'?

A.  It means it has the ability to inhibit the growth of bacteria without destroying the bacteria. For example a bacteriostatic cartridge will reduce bacterial colonization activity on the filter but will not eliminate it.

 Q.  Are either the RF05-7 or the NF-7 'Nano filter' (used in the Outback-Plus system) bacteriostatic?

A.  Yes, both of these filters are bacteriostatic -- which means any bacteria captured by the filter does not have the ability to multiply. This is important because eliminating the bacterial growth reduces the 'work' that the filter must do to remove bacteria as water flows through it - prolonging the life of the filter.


 Q.  How long has the Outback system been used to treat water of questionable quality?

A. For over 20 years. The original Outback Systems were sold primarily to relief organization for use in countries outside the United States. These systems have been used by organizations throughout the world to provide drinking water using contaminated water sources. What is considered the 'domestic version' of the Outback was made available to the general public in 2001.

 Q.  Who uses the Outback systems?

A.  The Outback is used on a daily basis by some of the largest relief and faith based organizations in the world as well as by a myriad individuals and small groups. They all use the Outback as their only method of water treatment. The Outback has also frequently sold as a stand-alone emergency preparedness product due to its reliability, portability, effectiveness, ease of use, and its affordability.

 Q.  Is it really necessary to worry about removing virus?

A.  Yes. There are multiple studies indicating the presence of viruses in groundwater. For example the most recent study taken from the Minnesota Pollution control agency, showed that 24% of all samples taken from the faucets in people's homes were virus positive. These viruses come from human fecal matter, are negatively charged, and can be transported through the soil. This study showing groundwater containing viruses is disproves the common belief, that "ground water is pure and pristine". For the complete study go to http://ehp.niehs.nih.gov/wp-content/uploads/120/9/ehp.1104499.pdf.

 Q.  Has the Outback been tested by an independent certified laboratory?

A.  Yes, multiple times. The Outback Systems have been has been tested multiple times by two different certified third party independent laboratories - one located here in the United States and the other - theonly WQA - USA recognized Laboratory in India and the first WQA recognized lab in South Asia. The Lab is accredited by NABL for Drinking Water analysis as per ISO/IEC 17025.


Q.  Is it mandatory to flush the Outback system prior to initial use?

A.  It is not necessary but it does help to flush any carbon fines that may be present in the multimedia post filter.

Q.  Are these carbon fines harmful?

A.  The carbon fines are not harmful if ingested.

Q.  How big is the Outback system?

A.  The smaller or "mini" version of the Outback System has 2 gallon upper and lower containers which, unassembled measure 9” x 9” x 10” and assembled measure 9” x 9” x 18”. The standard size uses a 2 gallon upper  container and a 5 gallon lower container, unassembled measuring 12” x 12” X 15” and assembled  measuring 12” x 12” x 24”.

 Q.  How much does the Outback system weigh?

A.  When not in use the mini Outback’s weigh 3.5 lbs and when in use and the lower bucket is full they weigh 20 lbs. The full size Outback Systems weighs 6 lbs when not in use and 45-48 lbs when the lower 5 gallon container is full.

 Q.  What is the storage life of the Outback and the Outback filters?

A.  The Outback Systems and filters have an indefinite shelf life if filters are left in original packaging, remain stored inside the Outback and the systems is not stored for long period of time in direct sunlight.

 Q.  Can you clean the Outback system filters?

A.  The Outback filters were purposely designed so that they could not be cleaned. A great concern is that cleaning a filter that is contaminated with a high percentage of a pathogenic microorganism leaves the individual at high risk of contaminating themselves causing illness.


Q.  How does the Outback compare to other methods of water treatment systems? A general comparison and discussion follows.

A.  Comparisons are always difficult. What research has shown is, in the event of an emergency "simple, reliable and effective" are the key elements required in any device on which you must depend -- be it a stove, water filtration device or your food supply. We believe that this is the reason so many private and government organizations have elected to use the Outback as their system of choice.

There are product manufacturers claiming their products are used by NASA or special forces in Iraq, or hikers and back packers while they scaled mount Everest. Who knows, maybe those claims are true. But it is important to remember we are not astronauts. We are not' special forces' soldiers and we are not members of that small percentage of the population who go on unimaginable expeditions. We are fathers and mothers who get up every day and go to work and hope and pray that our families will never be forced to face a devastating disaster. We watch and read the news and see it happen to others - and hope it will never happen to us. However, in the event we do face such a challenge, we want to prepare as best as we possibly can. As a part of that preparation, we want a water system that any member of the family can operate -- one that is simple, effective and reliable. The Outback Gravity-Powered Systems meet this need. This is evidenced by the fact that, in the aftermath of Katrina, when the Department Home Land Security (DHLS) requested a design for a water treatment system that could be used by the average American consumer in the event of a disaster, a mini version of the Outback Gravity-Powered System was their product of choice.

Q.   Are the Outback filters better than ceramic filters? What are the differences?

A.  The Outback filters are different than a ceramic filter in several ways.

                                                Bacteria Removal        Virus  Removal           Durable     no early exhaustion

Outback Plus Filter (NF)                99.9999%                      99.99%                      yes                      x

Outback Filter (FF)                         99.99%                   with chlorine or iodine      yes                      x

Ceramic Filter                                 99.99%                               0                            no                       -


VIRUS: The Outback-Plusf ilter (NF7) effectively removes viruses - a ceramic filter does not. Even the standard Outback filter (RF05-7) can be used in conjunction with Chlorine or Iodine to remove viruses. A ceramic filter cannot be used in this manner without quickly exhausting it. (The amount of media inside a ceramic filter is small when compared to the media in the Outback's multi-media cartridge and would quickly be exhausted when burdened by the removal of Chlorine or Iodine.)

BACTERIA: Most ceramic filters have a bacteria removal rate of 99.99 %, the Outback-Plus as a rating of > 99.9999%.   The standard Outback filter has a removal rate of 99.99% and is tested at a much higher standard than the standard under which ceramic filters are tested.

DURABILITY: A ceramic filter is very fragile and if dropped will break.  Neither the Outback RF05-7 or NF7 will break or crack when dropped.

LONGEVITY: Most ceramic filters contain a carbon core and once that carbon is 'exhausted', the filter has lost it's ability to remove organic matter from the water supply. Exhausted carbon can become a breeding ground for bacteria and can actually increase contamination in the water. The Outback uses a large capacity independent multimedia cartridge which provides a much greater capacity for the removal of organic and chemical contamination.  That function is separate and apart from the bacteria and/or virus removal filter.  This allows for replacement of this less expensive multi-media filter independently and as needed.

EFFECTIVENESS: The Outback system is tested using both GTW 1 and GTW 3 test water - challenges for general water filtration and purification systems simulating extreme real-world conditions, ceramics are tested using distilled water that has been inoculated with a pre prescribed amount of a specific microorganism. In short, the Outback is passing a much more stringent test protocol than the ceramic - and still out-performing it.

Q.  What does GTW mean? What is the difference between GTW 1 and GTW 3 test water?

A.  GTW stands for "general tap water".  The associated "3" indicates the characteristics of the water used by a laboratory when it is testing a water treatment system for effectiveness. The higher the number the tougher the challenge water.  Most water treatment systems tested never face the rigid specifications of GTW 1 or GTW 3, but rather are tested using distilled water which is inoculated with a specified microorganism. The Outback is tested against both standards GTW 1 and GTW 3 with GTW3 test water containing a much more difficult concoction of contaminates such as extreme pH, levels temperature variations, high turbidity, TOC and TDS levels - all creating conditions making the purification more difficult than  in GTW 1 waters. In addition, the Outback Systems are "cycle tested", meaning that, at pre determined times during the testing process the testing stops for 48 hours and the system being tested is left to "rest" with no water passing through the filters. During this period of "rest" the challenge micro-organism multiplies and builds up on the filter.  When testing is resumed, many filters allow "break-through" or allow a large amount of the micro-organisms to migrate through the filter. The Outback passes these tests with flying colors - showing no such break-through.

Q.  How can the Outback system produce so much water through a gravity powered process with so little pressure to push the water through the filters.

A.  The filter design of the Outback Systems have very high hydrophilic properties.

Q.  What does hydrophilic mean?

A.  Hydrophilic is having the characteristic of absorbing water. Example: Cotton is a hydrophilic fiber. Many filters contain hydrophobic characteristics which repels water, for them to work there must be a certain amount of pressure to push the water through the filter media. . Example: Nylon is a hydrophobic fiber.

Q.  Do you have to use any chemicals with the Outback Systems for them to be effectively remove bacteria, cyst and virus?

A.  The Outback Plus needs no chemical additives to remove bacteria, cyst and virus. The standard Outback is very effective in removing bacteria and cysts without the use of any chemical additives. Chlorine or Iodine can be used with the standard Outback if virus removal is desired.

Q.  What do 'nominal filtration' and 'absolute filtration' mean?

A.  These terms refer to the approximate size particle, the majority of which will pass through a filter, based upon its rating. The rating is usually in a micron size. A nominal filtration rating is generally interpreted as meaning that 85% of the particles (the size of its rating) will be retained or 'stopped' by the filter. An absolute filtration rating states that 99.9% or essentially all of the particles (larger than a specific micron rating) will be trapped on or within the filter.

Q.  In the event of an emergency can you recycle your own urine through the Outback?

A.  Healthy urine is not toxic. However, it contains compounds eliminated by the body as undesirable, and can be irritating to skin and eyes. After suitable processing it is possible to extract potable water from urine. The US Army Field Manual advise against drinking urine for survival. These guides explain that drinking urine tends to worsen, rather than relieve dehydration due to the salts in it, and that urine should not be consumed in a survival situation, even when there is no other fluid available. In hot weather survival situations where other sources of water are not available, soaking cloth (a shirt for example) in urine and putting it on the head can help cool the body.

Q.  Has ESP produced other water purification systems?

A.  Yes, the HLS-1 Gravity Powered Water Purification System was developed in response to a Source Sought solicitation by the National Protection Center (NPC) of the U.S. Army Natick Soldier Research Development and Engineering Center. The NPC was sponsored by the department of Homeland security to identify or develop a near-term solution for a personal portable water purification system that was low cost, easy to use, had a long shelf life and could pass NSF P248 , Emergency Military Operations Microbiological Water Purifiers.

Q.  Can I get a system for my home that contains the same type of filtration as the Outback systems?

A.  You can now. ESP is using the latest Nano technology in filters/filtering systems that work with standard household pressure as well as filters that can handle flow rates of up to 3-4 gallons per minute. In many cases if you already have a filtration system in your home there is no need to replace it. You can simply change out your old filters with the newest filter technology offered by OutbackWater.

Q.   Do you ship the Outback to customers who live outside the United States?

A.   Yes, the Outback Systems are shipped to customers through-out the world.

Q.  What is the warranty on the Outback and the Outback components?

A.  The Outback Systems are covered under a normal use one year warranty.

Q.  Where are the Outback components and systems made?

A.  All of the Outback components are made in the United States except the pre-filter net and sleeve, which are made in Ontario Canada.

Q.  Where are the Outback Systems assembled?

A.  The systems are assembled, packaged and shipped from the Pearl Buck Center in Eugene, Oregon.

Q.  Is there a patent on the Outback system?

A.  Yes, there is currently a patent pending on the Outback Plus systems.

Q.  How long has your company been in business?

A.  We have been in business since June of 1993.

Q.  How can I order the Outback?

A.  There are several ways to order the Outback Gravity-Powered Systems. Start with the Outback Page on our website: 


or call us at 844.377.7873