Supreme Heating’s innovative, diamond-shaped bubble pool covers will increase heat retention, eliminate evaporation almost completely and reduce running costs in terms of maintenance and pool chemical consumption. An outdoor pool gains heat from the sun’s free energy and loses heat through water evaporation and convection. Solar pool covers are a must-have addition to your swimming pool or spa. Once you have heated your pool, the best way to ensure the heat stays there all year round is with a solar cover. A pool cover maximises the absorption and retention of heat from the sun and will increase the pool temperature by as much as 8°c.