The current lack of cost-effective and efficient cleaning technologies in both freshwater and marine larval hatchery tanks in recirculating aquaculture systems is a substantial drawback for both technology-providing and fish farming SMEs in Europe. Bacterial biofilms constantly and quickly develop on all surfaces in the tanks and endanger the production of high quality and quantity fry which is an absolute must for successful aquaculture operations in a growing, highly competitive market. Thus, there is an enormous need to find a sustainable technology for an efficient cleaning of the tank surfaces and the standpipe meshes. Meshes on the standpipe, which prevent the aquatic life from being sucked away from the water flow, need to be continuously replaced due to the formation of biofilms, resulting in high material and labour costs. CLEANHATCH aims to develop and implement a new technology that constantly sweeps the sides and base of the tanks as well as backwashes the meshes whilst injecting ozonated water into the tank directly over the tank surfaces. Compared to the state of the art, the new technology has the advantages of (a) cleaning the tank's sides, base and standpipe's meshes saving considerable man-hours, (b) disinfecting the surfaces and meshes through the focused injection of the ozonated water, (c) reduce the amount of mesh required and focus the mesh to the bottom part of the tank where the water is best extracted from. CLEANHATCH will develop, implement, test and optimise the new technology under pilot and real production conditions, aiming to achieve a marketable product within one year after project termination. The project is centred on complementary technological problems and innovation needs of the three participating SMEs. By providing technology applications that do not presently exist in the market, the project will bring the participating SMEs to the forefront of the hatchery technology market, strongly improving their competitive position.