Multi-media sand filters normally consist of three media layers (ie. support base gravel, micro screened sand and anthracite) and are a very economical means of primary filtration to remove the bulk of suspended solids. They are particularly efficient on surface waters for the removal of grit, sediment, turbidity and organic matter but also widely used on oxidised iron ('rust') and other precipitated contaminants such as manganese or scale particles.
Multi-media filters are periodically backwashed (either automatically or manually) by simply reversing the flow and this flushes to waste the accumulated sediment and also regrades the filter media layers.
Operation and maintenance is extremely simple. After initial set-up, the system is virtually self sustaining. With the Logix Controller, back-flushing and clearing of trapped contaminates occurs automatically.