Wellmate fiberglass pressure tanks are a type of water storage tank that is prevalent in well water systems. These tanks are built to minimize pump cycling, supply steady water pressure, and hold water for usage in situations where demand surpasses the well pump's capability for more information please ask. Wellmate fiberglass pressure tanks are a type of water storage tank that is prevalent in well water systems. These tanks are built to minimize pump cycling, supply steady water pressure, and hold water for usage in situations where demand surpasses the well pump's capability for more information please ask.