A liquid storage system comprising: a tank for containing a liquid, the tank enclosing a liquid storage space; multiple layers of a fabric material; and attachment means attaching the multiple layers of the fabric material to an internal surface of the tank. The attachment means may comprise a non-permeable envelope attached to the internal surface of the tank. The multiple layers of the fabric material may be enclosed in the envelope such that the multiple layers of a fabric are isolated from a fluid in the tank. The envelope may contain a fluid (e.g. air) in addition to the multiple layers of the fabric material.