The Water Butt FreshaTank Microbial Disc is a superb water butt cleaner and water butt freshener. Just pop it in your water butt to enjoy fresh, clean and odour-free water. Made from copper and silver, FreshaTank uses the natural biocidal effects of real silver that, when immersed in water, destroy germs including viruses, bacteria, fungus and water-borne diseases! Everlasting, one time purchase and under £15.00! Water stays fresh and Odour Free Environmentally Friendly, made from natural materials Safe to use with fish tanks High quality, hygienic, 100% reliable - A unique, money-saving addition to your home Just place the FreshaTank in your water butt or fish tank and it will immediately begin to work. Analysis of the efficiency of Fresha Tank conducted by Intertek. Conclusion data from this study demonstrate that the viability of bacteria could be affected by different parameters such as a high stress, the porosity of the material, the natural desiccation of suspensions, the antimicrobial disposition at the surface, and the presence of surfactants. All these parameters have to be controlled as seriously as possible to determine the real antimicrobial activity of each sample. \"These results would show important decrease of all bacteria tested in contact with the product at 24hr time contact. To conclude, the inhibitory effects are an intrinsic property of the material.\" **Only suitable for waterbutts with lids or avaliable access to place inside.**