Water filters remove contaminants from water. Those contaminants are trapped and will clog the filter. Removing these contaminants allows the filter to function properly. Some filters use backflushing to clean the filter and remove the trapped contaminants.
Backflushing a water filter involves pushing clean water through the filter in the opposite direction of the normal water flow. The trapped contaminants are pushed out of the filter allowing normal water flow once again.
Backflushing is a simple process that requires a syringe that is normally included with the filter. Fill the syringe with clean water and place the nose of the syringe at the output side of the filter. Push the clean water backwards through the filter. Repeat this process as needed to clear the filter. You can then use the filter normally once backflushed. The total time to completely backflush a filter should be less than a minute or two.
You can also use the backflush syringe for cleaning. The syringe can create a pressurized water stream that can be used to rinsing wounds or cleaning equipment. When treating a wound make sure that the wound is clean before applying bandaging or clotting agents. The suction created by the syringe could be used to extract water from difficult places. ALWAYS carry the syringe with the water filter.