The FilterPen is a handy water filter in the form of a straw which filters the water by means of X-Flow micro filtration membranes. The membranes have an average pore diameter of 0,18 micrometers and a maximum pore diameter of 0,25 micrometers. It therefore removes mainly bacteria and protozoa. Viruses are not removed because they are smaller than the pores. If there are indications that the water to be purified is contaminated with viruses or if there are doubts about this, prior treatment should be given to the water before using FilterPen.
|- High quality assurance, since each FilterPen is tested individually for its effectiveness.
- Fail safe system: filter will block when seriously fouled.
| - Low capacity which concerns short lifespan|
- Not suitable for long term use
The flow rate is 0,5 L/min at 0,1 bar. It is suitable for purification of about 100 litres of water, depending on the quality of the water to be purified and whether the instructions for maintenance and cleaning are followed.
The filterpen is not intended for Brackish or seawater. Always use water from the cleanest source available. Avoid filtering cloudy water with less than 30 cm of visibility), as this will result in the membranes becoming blocked sooner. Allow floating particles in the water to settle first. The FilterPen does not remove chemicals, so choose a water source which is as far as possible from agricultural and industrial areas.
Construction, operations and maintenance
The FilterPen weighs just 30 grams. The length is 200 mm with a diameter of 16,20 mm. The FIlterPen is used like a straw.
Ensure that the FilterPen is always clean and dry. After use, the remaining fluid can easily be removed by shaking out the straw in the air. Take care the mouthpiece is carefully cleaned and replace the cap. Avoid exposure to shocks such as hitting other objects or freezing of wet/damp membranes.
Before storing the FilterPen for a longer period of time, first clean it. Cleaning tablets and pipette are also supplied to clean the membranes. A complete set of instructions on how it should be done is provided with the product.
The filterpen Quite sensitive to shocks, so avoid dropping or collisions. However, as far as proper maintenance is conducted, no real damage should occur.
No possibility for local manufacturing. Filterpens are manufactured by NORIT Filtrix B.V. They are tested by KIWA water research using Pseudomonas Diminuta and VItens using E.coli
Once used for the first time the FilterPen can be used for up to three months. Bacteria in the FilterPen will duplicate in time which will ultimately result in clogging of the membranes. Therefore disposal is advised after three months.
Once you have used all the FilterPen cleaner tablets, it is also advised to dispose the FilterPen and use a new one. The FilterPen is intended as a disposable product in order to guarantee optimum retention of microorganisms.
- Free mold designs are available from CAWST
|Capital cost||Operating cost||Replacement cost||Estimated 5 year cost||Cost / metre cubed treated|
|  US$ 64 = €45,7
 £ 13,50 = US$ 21,97 = €15,7
|US$ 0||US$ 0||US$ 12-30||  €457|
- Water Purification. Pens and other small, portable methods.