The existing Pipis(shellfish) holding-purging system needed a lot of cleaning, with sand constantly blocking the pumps and filter beds, and this in turn affected the water quality. A new innovative design tank was constructed. It was decided that the best way forward was to install two complete recirculation systems. MultiCyclones were used to separate out the sand and large particulate matter discharged by the pipis. For this set-up, removing the sand in an easy and manageable way was one of the most difficult hurdles to overcome, but also one of the most necessary.