A kit for use with a recirculating cooling system includes a bag. The bag includes a first wall, a second wall opposite the first wall, and a side wall defining a reservoir configured to retain a fluid therein. A first port is defined through the first wall and a second port is defined through the side wall or the second wall. The bag is configured to maximize a temperature differential between a fluid proximate the first port and a fluid proximate the second port. Further, the bag is collapsible.