A thread-based filter for filtering a fluid, comprising: a thread-based medium comprising multiple threads; a tube comprising a first opening and a second opening, wherein: the tube at least partially houses the thread-based medium, the thread-based medium having a first end oriented towards the first opening and a second end oriented towards the second opening, the threads are oriented lengthwise along the length of the tube and extend between the first and second ends of the thread-based medium, the thread-based medium is configured to move lengthwise along the tube, the thread-based medium is configured to trap impurities present in the fluid flowing substantially lengthwise along the threads from the first opening to the second opening during a filtration mode, and the thread-based medium is configured to release impurities into a fluid flowing substantially lengthwise along the threads from the second opening to the first opening during a washing mode; a plate that provides one or more passageways for the fluid to flow through the plate, said plate being configured to move lengthwise along said tube, wherein: the threads at the second end of the thread-based medium are attached to said plate, and the threads at the first end of the thread-based medium are unattached and exposed to the incoming fluid to be filtered during the filtration mode, the tube and the motion of the thread-based medium are configured to provide a varying inter-thread spacing within the thread-based medium when the thread-based medium is moved lengthwise along said tube from the filtration mode to the washing mode, thereby providing a smaller inter-thread spacing during the filtration mode and providing a greater inter-thread spacing during the washing mode. a thread-based medium comprising multiple threads; a tube comprising a first opening and a second opening, wherein: the tube at least partially houses the thread-based medium, the thread-based medium having a first end oriented towards the first opening and a second end oriented towards the second opening, the threads are oriented lengthwise along the length of the tube and extend between the first and second ends of the thread-based medium, the thread-based medium is configured to move lengthwise along the tube, the thread-based medium is configured to trap impurities present in the fluid flowing substantially lengthwise along the threads from the first opening to the second opening during a filtration mode, and the thread-based medium is configured to release impurities into a fluid flowing substantially lengthwise along the threads from the second opening to the first opening during a washing mode; a tube comprising a first opening and a second opening, wherein: the tube at least partially houses the thread-based medium, the thread-based medium having a first end oriented towards the first opening and a second end oriented towards the second opening, the threads are oriented lengthwise along the length of the tube and extend between the first and second ends of the thread-based medium, the thread-based medium is configured to move lengthwise along the tube, the thread-based medium is configured to trap impurities present in the fluid flowing substantially lengthwise along the threads from the first opening to the second opening during a filtration mode, and the thread-based medium is configured to release impurities into a fluid flowing substantially lengthwise along the threads from the second opening to the first opening during a washing mode; a plate that provides one or more passageways for the fluid to flow through the plate, said plate being configured to move lengthwise along said tube, wherein: the threads at the second end of the thread-based medium are attached to said plate, and the threads at the first end of the thread-based medium are unattached and exposed to the incoming fluid to be filtered during the filtration mode, the tube and the motion of the thread-based medium are configured to provide a varying inter-thread spacing within the thread-based medium when the thread-based medium is moved lengthwise along said tube from the filtration mode to the washing mode, thereby providing a smaller inter-thread spacing during the filtration mode and providing a greater inter-thread spacing during the washing mode. the threads at the second end of the thread-based medium are attached to said plate, and the threads at the first end of the thread-based medium are unattached and exposed to the incoming fluid to be filtered during the filtration mode, the tube and the motion of the thread-based medium are configured to provide a varying inter-thread spacing within the thread-based medium when the thread-based medium is moved lengthwise along said tube from the filtration mode to the washing mode, thereby providing a smaller inter-thread spacing during the filtration mode and providing a greater inter-thread spacing during the washing mode.