The Eflo UFBF is a highly efficient biological process utilising beneficial bacteria to reduce harmful elements to acceptable levels. The filters can operate in an aerobic or anaerobic manner. Nitrate removal in drinking water is achieved in an anaerobic manner by supplying the biomass within the filter vessels with a suitable carbon source such as methanol or acetic acid. The nitrate is reduced and converted by the beneficial bacteria to nitrogen gas and water. Some 93% reduction is typical. The efficiency of the process is determined by the media within the filter vessels. This supports high levels of fixed film growth. Eflo use Filtralite media, an expanded clay product in various grades but typically providing very high specific surface areas and light density. As with all biological processes, there will be a build up of excess biomass and the Eflo UFBF process allows for the automatic removal and collection of this waste.