Candle type pressure filters are used extensively for polishing and solids recovery duties particularly in lithium conversion to carbonate, hydroxide or via DLE but also in Rare Earth processing plants. They require specific operating considerations compared to the more commonly used pressure filters such as filter presses, media filters or continuous filters which will be discussed. Those pressure candle filters operate across a wide range of feed solids from almost zero (SX feed or thickener overflow polishing) to about 15 per cent solids (RE recovery), with a limit defined by longer relative downtime and the need to refill the filter with unfiltered slurry after each discharge. While they accept a wide range of feed solids their operation must assure that no overfilling occurs, requiring close attention to process control. The batch operation with constant feed flow/increasing filtration pressure followed by decreasing flow/constant pressure will be discussed, and how to optimise the overall filter capacity. The versatility of those filters covering slurry and dry cake discharge, optional cake washing, (displacement or spray washing), cake blow-drying, using filter aids as pre-coat and/or body feed at a wide temperature range with plenty material of construction choices also requires a detailed understanding of possibilities and limitations. Those considerations will be discussed based on typical lithium conversion applications such as impurity removal, Glauber salt and lithium carbonate filtration examples together with process options and combinations - how candle type filters work best in combination with centrifuges, thickeners or vacuum filters.