Backwashing is a flushing process that is carried out in the opposite direction of flow. Imagine, for example, a pipe in which water flows from left to right and flows past a membrane for filtering. Over time, due to particles filtered out of the water, the membrane will become clogged and allow less and less water to pass through. In a BACKWASHABLE FILTER, the water can now exceptionally flow from right to left for filtering, dissolving the deposits on the membrane and transporting them into the waste water. BACKWASHABLE FILTERS are used, for example, in domestic water or swimming pool technology.