A portable filter and filter system. The filter has a filter housing defining a liquid channel from an inlet to an outlet. The portable filter includes a liquid filter located in the filter housing, a mouthpiece mechanically associated with the dispensing end of the filter housing, and a liquid receiving means connected to the receiving end of the filter housing. The device can include a pre-filter assembly of which the liquid receiving means is a part. The liquid receiving means can include multiple connection members to receive liquid from a variety of liquid sources. The filter can be combined with a liquid container to form a portable filter system. The container can be a flexible bladder having a strap to connect the filtration device to the bladder.