The Water Filter Purifier Soft Flask removes waterborne viruses, bacteria and protozoa, while also filtering or reducing a broad range of other contaminants.

Waterborne pathogens include:

- 99.99% Viruses
- 99.9999% Bacteria
- 99.9% Protozoa, including Giardia and Cryptosporidium

Other filtered or reduced contaminants include:

- Dirt, sediment and suspended particles
- Chlorine
- Volatile organic compounds
- Selected heavy metals, including lead, arsenic and chromium
- Microplastics
- Endotoxins
- Colloids
- Trace pharmaceuticals
- Transparent exopolymer particles and other polysaccharides

The filtration process can also improve the taste, odour and clarity of water.

Yes. The purifier cartridge inside the Soft Flask is designed to remove 99.99% of viruses, 99.9999% of bacteria and 99.9% of protozoa.

The complete cartridge has been independently tested for microbiological performance by an ISO/IEC 17025:2017-accredited laboratory. 

Its USA-made Disruptor™ filter material has also been tested against relevant NSF/ANSI 42 and 53 requirements, while finished cartridges undergo batch testing during production to help maintain consistent quality and performance.

It’s a scientific way of saying how many microorganisms a purifier removes from water. The higher the number, the more it removes. For example, 4-log means removing 9,999 out of every 10,000 viruses — the same as 99.99% removal.

Our cartridge’s removal levels are:

- 4-log for viruses = 99.99% removal.
- 6-log for bacteria = 99.9999% removal.
- 3-log for protozoa = 99.9% removal.

The filter uses Disruptor™ technology to capture contaminants through mechanical filtration and electro-adsorption.

Disruptor™ is an electropositive, wet-laid nonwoven medium with a pore structure of approximately 1.2 to 1.5 microns. It captures contaminants in two ways:

- Larger particles are trapped mechanically within the filter structure.

- Smaller, negatively charged contaminants are attracted and bound through electro-adsorption, which enables the cartridge to capture microscopic pathogens including viruses, bacteria and protozoa.

This enables the cartridge to capture microscopic contaminants, including viruses, bacteria and protozoa, that mechanical filters with comparable pore sizes may not remove.

Disruptor™ is the specialist filter material inside our purifier cartridge. It uses a network of fine fibres with a natural positive charge to attract and hold tiny contaminants, including bacteria, viruses and other particles. 

This means it can capture contaminants much smaller than the gaps between its fibres. This lets water flow easily through the gaps while trapping contaminants in the filter material, helping you purify water as you drink.

Electro-adsorption uses a positive charge to attract and bind negatively charged contaminants as water passes through the filter.

The mineral-based crystal structure within the Disruptor™ medium creates a natural positive charge when it comes into contact with water. Many pathogens, heavy metals and fine particles carry a negative charge and are attracted to the positively charged filter medium.

This allows the system to capture contaminants much smaller than the filter’s physical pore structure.

Yes. The filter can improve the taste and odour of water by reducing chlorine and selected chemicals and organic contaminants.

Powdered activated carbon, also known as PAC, is incorporated directly into the Disruptor™ filter medium rather than being housed in a separate carbon block. This provides taste and odour reduction without significantly restricting the water flow.

No, the filtration process retains naturally occurring dissolved minerals, helping preserve the water’s natural taste.

Disruptor™ has an open structure with larger pores that allow water to flow through easily. Instead of relying solely on tiny pores to trap contaminants, it also uses a positive electrical charge to attract and hold them, even those much smaller than the pores.

This allows the Soft Flask to purify water as you drink or decant it.

No electricity, pump or chemicals are required. Purification happens as you draw or gently squeeze water through the cartridge.

The Water Filter Purifier Soft Flask is available in 500ml and 1000ml capacities.

The 500ml Soft Flask is designed to fit many running-vest pockets, making it suitable for trail running, fast hiking and other activities where low weight and easy access are important.

The 1000ml version provides additional capacity for longer outings and travel.

The 500ml version is designed to fit many running-vest flask pockets.

Running-vest pocket sizes vary by brand and model, so check your vest and the Soft Flask dimensions before purchasing.

To open, first twist the cap to the unlocked position, following the markings on the lid, then lift it. Do not lift or pull the cap while it is locked, as this may damage the hinge.

To close, lower the cap over the mouthpiece, then twist it back to the locked position. Keep it closed and locked when not in use to protect the mouthpiece from dirt and contamination.

Yes. Water is purified as it passes through the cartridge

No. The cartridge does not need to be soaked or primed.

Install it correctly, fill the Soft Flask with freshwater, secure the lid and drink through the valve. It may take a few initial sips or a gentle squeeze to draw water completely through a new, dry cartridge.

Use gentle, steady pressure. Do not twist, crush or force the flask if the water flow becomes restricted.

If unusually high pressure is required, make sure the twist valve is fully open and the cartridge is installed correctly. Replace the cartridge if normal flow does not return.

Open the twist valve and gently squeeze the Soft Flask, using steady pressure to push water through the cartridge and into a clean bottle or cup.

Keep the drinking valve clear of the receiving container and make sure untreated water on your hands or the outside of the flask doesn't drip into it. If water is difficult to squeeze through, do not force it.

The replaceable cartridge can treat up to 250 litres of water.

This is a maximum capacity. Actual filter life depends on the quality of the source water. High levels of sediment, silt and other contamination may block the cartridge sooner.

Once the cartridge has been wetted and brought into use, replace it after a maximum of three months, when it reaches 250 litres or when water no longer passes through it, whichever occurs first.

An unopened cartridge has a shelf life of up to 10 years when stored correctly in its original sealed packaging.

Once the cartridge has been wetted and brought into use, its three-month usage period begins.

Replace the cartridge when any of the following applies:

- Three months have passed since it was first used.
- It has treated up to 250 litres.
- Water no longer passes through it.
- The flow has become unacceptably slow.
- The cartridge may have frozen or been damaged.
- It has been exposed to water hotter than 50°C.
- You are uncertain whether it has been stored or handled safely.

The 250-litre capacity is a maximum and may be reduced by poor-quality or sediment-heavy source water.

Yes. The filter cartridge is replaceable and can be purchased here.

Always use a genuine Lifesystems filter cartridge that is compatible with the Water Filter Purifier Soft Flask.

When you first use the cartridge, turn the indicator ring to show the month when it will need replacing, three months later. For example, if you start using it in June (number 6), set the ring to September (number 9). 

The ring reminds you to replace your cartridge. Replace it sooner if you have filtered 250 litres of water, it becomes blocked or you think it may have been damaged.

The flow will gradually slow as the cartridge collects sediment and other contaminants. This may happen more quickly when filtering cloudy or silty water.

Check that the cartridge is installed correctly and that the twist valve is fully open and clear. If the flow remains unacceptably slow, replace the cartridge.

Do not backwash the cartridge, force water through it at high pressure or clean it with soap or chemicals.

The Soft Flask is intended for freshwater from sources such as:

- Rivers and streams
- Lakes
- Freshwater springs
- Campsite and mountain-hut taps
- Public taps and drinking fountains
- Hotel and hostel taps
- Bottled water of uncertain quality

Always choose the clearest and cleanest freshwater source available.

Yes, but very cloudy or silty water will reduce the flow and shorten the cartridge’s usable life.

Where possible, allow sediment to settle and collect the clearer water from the top. You can also pass the source water through a clean cloth before filling the Soft Flask.

Pre-filtering only removes larger particles. The water must still pass through the purifier cartridge before drinking or decanting.

No. The cartridge does not remove dissolved salt and must not be used with seawater, brackish water or other highly saline water.

No. Do not use the Soft Flask to treat water affected by severe chemical or industrial pollution.

This includes water affected by industrial spills, fuel, mining waste, radioactive contamination or extremely high concentrations of heavy metals.

Avoid water containing a visible blue-green algal bloom or water covered by an official warning about algal toxins. Choose another water source.

No portable purifier suits every water source. The Soft Flask protects against the contaminants it has been designed and tested to remove, but it cannot remove salt from seawater or brackish water, or make heavily chemically polluted water safe to drink.

You should also avoid water with high tannin levels. These naturally occurring plant compounds can give water a yellow or brown colour and an unpleasant taste. Although tannins themselves are not harmful to humans, they can reduce the effectiveness and lifespan of the cartridge’s activated carbon filter.

Choose clear, flowing fresh water wherever possible.

Yes. Source water can be pre-treated with a suitable Lifesystems chlorine or chlorine-dioxide water treatment before it passes through the filter.

Follow the treatment product’s instructions and allow the treated water to stand for at least 30 minutes before filtering or drinking it. Pre-treatment should take place in a suitable separate container.

Never exceed the treatment product’s recommended dose.

No. The cartridge is designed to remove viruses, bacteria and protozoa without routine chemical pre-treatment.

Chlorine or chlorine dioxide may be used as an additional treatment stage where circumstances warrant it, provided the treatment instructions are followed correctly.

No. Do not add electrolytes, flavourings, squash, energy powders or other drink mixes to water that will pass through the cartridge.

Instead:

1. Fill the Soft Flask with plain freshwater.

2. Pass the water through the filter.

3. Decant the purified water into a separate clean bottle or cup.

4. Add the electrolytes or flavouring to that separate container.

Drink-mix ingredients and undissolved residue can clog the filter, restrict the flow and encourage unwanted growth.

No. Only freshwater should pass through the cartridge.

Do not use the Soft Flask to filter juice, fizzy drinks, alcohol, milk, tea, coffee or other beverages.

Remove the filter cartridge before cleaning.

Hand-wash the Soft Flask, lid, cap, twist valve and other non-filter components using warm water and mild washing-up liquid. Rinse thoroughly and let each component dry completely.

Do not place the Soft Flask or any of its components in a dishwasher.

No. Do not wash the cartridge with soap, detergent, bleach or other cleaning products, and do not place it in a dishwasher.

Do not attempt to backwash the cartridge.

After use:

1. Remove the cartridge.

2. Shake out as much excess water as possible.

3. Allow the cartridge to air-dry thoroughly. This may take two to three days.

4. Hand-wash and completely dry the Soft Flask, valve, cap and other components.

5. Reassemble the flask once everything is dry.

6. Store it in a clean, dry place away from sharp objects, excessive heat, freezing temperatures and direct sunlight.

When using the Soft Flask again, install the cartridge, fill the flask and draw water through the valve. No separate priming or soaking process is required.

The Soft Flask can be carried in cold conditions, but a wet cartridge must not be allowed to freeze.

Freezing may damage the filtration medium and make the cartridge unsafe even if no damage is visible. Keep the flask and cartridge insulated and close to your body in freezing conditions.

If you think a wet cartridge has frozen, replace it before using the Soft Flask again.

Do not expose the cartridge or Soft Flask to water hotter than 50°C. Do not use boiling water or put the flask in a microwave.

Replace the cartridge if you believe it has been exposed to excessive heat.

Untreated water on your hands or the outside of the Soft Flask can transfer to the drinking valve. 

To reduce the risk:

- Fill the flask carefully, keeping the drinking valve away from untreated water.

- Clean and dry your hands after filling.

- Wipe away any untreated water from the outside of the flask.

- Avoid touching the drinking valve or inside of the cap with dirty hands.

- Make sure the lid is fully tightened and the mouthpiece is securely fitted before drinking or squeezing the flask.

- Keep the drinking valve covered when not in use.

- Keep clean drinking containers separate from equipment used to collect untreated water.