Seeded Reverse Osmosis (SRO) actively promotes precipitation of CaSO4 prior to membrane treatment, reducing the corrosion of the membrane walls and fouling by salt precipitation. This pre-treatment method involves a suspension of seed crystals introduced into the effluent via recycling of waste slurry. This crystal slurry is approximately 10% solids and a tubular reverse osmosis (TRO) system is required because hollow fibre systems are unsuitable because of fouling. A number of disadvantages exist with SRO despite high salt and water recovery and reduced costs. Energy consumption is high; there is poor control of CaSO4 seed and seed solution controls.