NOVELTY - The collector (50) has a square or rectangular frame (51) housing a bladder, where the bladder defines an internal cavity. An outlet (54) of the bladder ingress and egress of water, where the bladder comprises a broad front face with shallow thickness exposed to sunlight. The bladder made of polymeric material e.g. polyvinyl, polyethylene, polybutylene or polypropylene material or mixtures. An inlet (53) and the outlet of the bladder are diametrically opposed corners of the bladder. A capacity of the bladder being ranges between 9 to 11 liters.    USE - Solar collector for a solar hot water system and a solar hot water installation (all claimed) on a roof of a building in domestic applications. Uses include but are not limited to heating water for showering, clothes washing, kitchen use, pool and spa heating.    ADVANTAGE - The collector heats the water below boiling temperature of the water, where the water is selected from a scarce resource, so that the water wastage following vaporization is eliminated, thus reducing the water wastage and eliminating the potential for fouling a drinking water supply. The collector enables assisting to resist dissipation of the heat from the bladder to increase the heating effect of the water within the bladder so as to increase the efficiency of the collector. The polymeric bladder prevents the resist damage when the water is provided within the bladder freezes, prevents the effects of extreme temperature while providing high tolerance to withstand impacts. The bladder is insulated and sealed to improve heat transfer within the collector to retain the heat within the bladder for a longer period of time and to allow for better absorption of heat into the bladder. The number of installation personnel required to install a solar hot water system is reduced by installing both the collector and a tank together. The collector enables providing light weight components for sufficiently lifted by a single installation person without the need for crane assistance. The separate formation of the collector and the tank reduces the bulk of components inside the collector, thus increasing the ease with the single installation person handling the components. The collector reduces labor intensity.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a solar hot water system comprising a storage tank.    DESCRIPTION OF DRAWING(S) - The drawing shows a front view of a solar collector.    Solar collector (50)    Square or rectangular frame (51)    Inlet (53)    Outlet (54)    Sheet (57)