Crystal Pool (PVT) Ltd. Sangabo Mawatha, Anuradhapura 0716552500 crystalpool.lk Sand filters are cleaned by backwashing, which includes reversing the h2o stream through the filter, and flushing the dirty water into a waste line. Phone us now, our educated sales staff is listed here to reply all of your queries! https://maps.google.com/maps?ll=8.310069,80.40174&z=16&t=m&hl=en&gl=LK&mapclient=embed&cid=3232803549851328223