... 2. two glass fibre pre-filter 3.150kg quartz sand filter 4. 50kg active carbon filter 5. water softener Dolphin RO ... treatment equipment adopts multi medium active carbon filter and PP sediment membranes filter as Pre-filter which can wipe suspending particles,dust, ... raw water complies with RO inlet requirement. Then RO filter can wipe dissolvable substance,bacteria,pesticide ,heavy metal particlea ...