A Water storage tank was imported to give customers the option of retaining 5000 liters of water which can be pumped back into your water tank once it has been cleaned.The tank is collapsible and expands once water is pumped into it,once water is returned to your freshly cleaned tank the storage tank is then folded up and returned to truck.This item was particularly useful for when we cleaned tanks on stewart island as there is no water delivery service there