Rain Water collected on the roof is very pure and clean. However, there are many substances, which get mixed with this pure Water on the roof (leaves, bird droppings, dust etc). These impurities need to be filtered before the rainWater is stored. RAINTAPTM Popup Filter is a simple device, which is very effective and user friendly. This filter has been successfully installed in many residential and smaller institutional or industrial buildings. This RAINTAPTM Popup Filter is simple in design and is flexible to install in varying field conditions.An important feature in filtering rainWater is the separation of the first flush of rainWater from the relatively cleaner and purer subsequent rain.